Baked Japanese Sweet Potatoes with Miso Tahini Butter

If you’ve ever had a warm baked sweet potato slathered in butter, you know that it’s one of life’s greatest pleasures. It’s such a simple meal but it’s beyond satisfying.

I wanted to evoke that same comforting feeling but introduce an elegant, modern spin. I often describe my recipes as vegan comfort food with an elevated or unique twist.

Like here, instead of plain old butter, I infuse the flavors of miso, sesame, and lime into the (vegan) butter. And instead of regular sweet potatoes, I use Japanese sweet potatoes because they are truly the best. I’m a big fan of miso butter, as evident in my Miso Butter Mushroom Risotto, Miso Butter Mashed Potatoes, and Creamy Umami Noodle Soup with Crispy Mushrooms! 

But this time, I decided to add a few extra ingredients for extra pizzaz and flavor!

All About Japanese Sweet Potatoes

The first time I had a Japanese sweet potato, I felt like I had been missing out on something magical my whole life. If you haven’t tried one yet, I can’t recommend it enough.

In Japan, sweet potatoes are referred to as Satsuma Imo. They are typically available year-round in Japan, but are most closely associated with autumn in Japan.

Japanese Sweet Potatoes vs. Sweet Potatoes

Japanese sweet potatoes, aka Murasaki sweet potatoes, have purple-pinkish skins and white flesh that turns golden when baked, as opposed to the orange-fleshed sweet potato.

Texture-wise, Japanese sweet potatoes are somehow drier and fluffier yet also creamier, thicker, and denser than standard sweet potatoes, which is why I adore them so much. Taste-wise, they’re incredibly sweet (even sweeter than the classic sweet potato) and have a slight chestnut flavor.

Where to buy Japanese Sweet Potatoes

You can find Japanese sweet potatoes at well-stocked grocery stores like Whole Foods and Trader Joe’s, specialty produce stores, farmers markets, Japanese grocery stores, and certain online retailers like Fresh Direct.

How to cook Japanese Sweet Potatoes

Two common methods for cooking Japanese Sweet Potatoes are baking and steaming. For baking, which is what I do in this recipe, I love using a relatively low heat (375°F vs. the 425°F I use for regular sweet potatoes) for a long baking period. This is how you get the the soft, luscious pudding-like interior without the potato drying out too much.

When baked properly, a Japanese sweet potato should almost melt in your mouth. The skins and edges get crispy, while the interior is buttery smooth and luscious. They’re so tasty you can eat them on their own, but they’re extra tasty when you load them up with this miso tahini butter.

Why you’ll like this recipe

Elevated comfort food. Take the down-home comfort of a baked sweet potato slathered in butter, and then level it up with a Japanese sweet potato slathered in the most umami-rich butter. It’s pure comfort food with a unique and elegant twist!

Extremely easy. All you need to do is pop some sweet potatoes in the oven and then mash a handful of ingredients into a buttery spread. It couldn’t be any simpler!

Crowd pleasing. Whether you serve this as a side dish, or slice the sweet potatoes into smaller pieces for an appetizer, this recipe is a guaranteed crowdpleaser. PS: no one will guess it’s vegan1

Flavor explosion. Miso paste + toasted sesame oil bring rich nutty umami flavors, which are enhanced by the sweetness from the sweet potatoes and a drizzle of agave, as well as the sourness from the lime. It’s truly a party for your taste buds!

Ingredient Rundown

Vegan Butter. These are Miso Tahini Butter stuffed sweet potatoes, so we have to use some good quality butter. Vegan butter, that is!

Vegan butter sticks soften just as easily as traditional butter, but if you forget to soften your butter, you can fast track the softening process by slicing it into small pieces.

Miso Paste. Another essential ingredient in a Miso Tahini Butter is, well, miso! If you’re familiar with my recipes, you know I adore miso paste. Miso is made from fermented soybeans and it’s a really concentrated form of umami. I love incorporating plant-based sources of umami into my savory recipes as often as possible because it brings that rich mouthfeel and flavor that everyone craves.

Tahini. The final main ingredient in a Miso Tahini Butter is tahini! Tahini (aka sesame seed paste) is another ingredient you’ll find frequently in my recipes. I love the creamy texture and nutty taste that it brings to both savory and sweet recipes.

That said, there is wide variation in tahini brands. Typically, tahini made with unhulled sesame seeds is bitter, whereas tahini made with hulled sesame seeds is not bitter and is creamier.

The tahini brands I love and recommend are Soom Tahini, Seed + Mill, or the Whole Foods 365 brand.

Toasted Sesame Oil. Keeping with the sesame seed flavor profile and family, I also add a splash of toasted sesame oil to this miso tahini butter for a rich, nutty, and toasty flavor.

Lime. I am obsessed with the lime-sesame flavor combination, so to complement both (a) the tahini, (b) the toasted sesame oil, and (c) the toasted sesame seeds, I add both lime juice and lime zest to the miso tahini butter. I also add a final sprinkle of lime zest at the end for an intensely bright, summery, citrusy flair.

Agave Nectar. To enhance all the savory umami goodness in this recipe (vegan butter, miso, toasted sesame oil, tahini), I add a bit of sweetness with agave.

Cilantro. For a final fresh, citrusy flavor, I garnish the baked and stuffed sweet potatoes with fresh cilantro (along with toasted sesame seeds and flaky sea salt).

How to make Baked Japanese Sweet Potatoes with Miso Tahini Butter

Wash or thoroughly scrub the Japanese sweet potatoes. I use a potato brush like this. Use a sharp knife to prick the potatoes all over. Transfer the potatoes to a parchment paper-lined baking sheet, or directly onto your oven rack.

Bake the potatoes at 375°F/190°C for 75 minutes (60 minutes for small potatoes; 85-90 minutes for large potatoes). Turn off the oven and let the potatoes rest inside the oven for 45-60 minutes.

Take the potatoes out of the oven and slice across the top. They should be extremely tender and soft on the inside. See that interior creaminess below!

I learned this close-the-oven-door trick from another food blog called Matcha and Tofu, and it works wonders!

 

While the potatoes are baking, make the miso tahini butter. Soften the vegan butter at room temperature until you can mash it with a fork.

Add the miso paste and butter to a medium or small bowl. Then add in the tahini.

Add the lime zest, toasted sesame oil, and agave nectar. Squeeze in the lime juice and add crushed red pepper flakes.

Use a fork or whisk to mash all the ingredients until smooth.

Slather the miso tahini butter inside the baked and sliced sweet potatoes. Top with cilantro, toasted sesame seeds, lime zest, and a pinch of flaky salt.

Tips for this Recipe

For the miso tahini butter, slowly with the miso paste, toasted sesame oil, lime juice, and agave. After mashing up the ingredients, taste and adjust accordingly. Add more miso for more intense sweet-saltiness, more sesame oil for a nutty rich taste, more lime juice for acidity, or more agave for a touch more of sweetness.

If the miso tahini butter is more on the melty side rather than creamed, pop it in the fridge for 20ish minutes until it reaches a spreadable consistency.

If you have leftover miso tahini butter, store the leftovers in an airtight container in the fridge for several days. You can spread it on toast, or on other roasted or steamed vegetables.

To turn this recipe into a main course, stuff some chickpeas or lentils into the buttered sweet potatoes. Recently, I served them with pan-fried chickpeas and it was such a hit with my family.

To pan fry chickpeas, head a bit of oil in a large frying pan, spread out the cooked chickpeas in an even layer, cook over medium-high heat for about 5 minutes, tossing only occasionally until they’re blistered in some spots. During the last minute of cooking, season with salt and pepper (I love using this Japanese chili pepper, Shichimi Togarashi) and a squeeze of lime juice.

To take this recipe over the top, sprinkle on some vegan furikake (a dried Japanese condiment typically made with sesame seeds, dried seaweed, dried fish, and sugar) or gomasio (a dried Japanese condiment made from sesame seeds and salt) on top. SO GOOD!

Substitutes for this Recipe

If you can’t find Japanese sweet potatoes where you live, you can substitute traditional sweet potatoes. To bake those, increase the oven temperature to 425°F (218°C). Lightly slash or prick the sweet potatoes several times with a sharp knife, place on a parchment paper-lined baking sheet, and bake for 45-55 minutes, or until the potatoes are fork tender and don’t give any resistance.

If you can’t find white miso paste, yellow miso is the best next option. Red miso is a lot bolder in flavor and can overwhelm other flavors, so try using half the amount called for in the recipe to prevent overpowering the other flavors.

If you give this Baked Japanese Sweet Potatoes with Miso Tahini Butter recipe a try, be sure to tag me on Instagram with your recreations and please comment with your feedback below!

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Baked Japanese Sweet Potatoes with Miso Tahini Butter

Nisha Vora

5 from 43 votes

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Baked Japanese Sweet Potatoes with Miso Tahini Butter is a crowd pleasing indulgent side dish! Includes tips on how to cook Japanese sweet potatoes, where to buy Japanese sweet potatoes, and the differences between Japanese Sweet Potatoes vs Sweet Potatoes.

Prep Time: 5 minutes mins

Cook Time: 2 hours hrs 15 minutes mins

Total Time: 2 hours hrs 20 minutes mins

Course: Appetizer, Dinner, Side Dish

Cuisine: American

Diet Vegan

Serving size: 4

Ingredients

• ▢ 2 pounds Japanese sweet potatoes

Miso Tahini Butter

• ▢ 5 tablespoons vegan butter, softened at room temperature
• ▢ 1 tablespoon white miso, plus more to taste
• ▢ 2 tablespoons good-quality tahini
• ▢ 1/2 of a medium lime, zested
• ▢ 1 ½ tablespoons lime juice, plus more to taste
• ▢ 1 teaspoon toasted sesame oil, plus more to taste
• ▢ 1/2 to 1 teaspoon agave nectar
• ▢ A few pinches of red pepper flakes

For serving

• ▢ 1 tablespoons toasted sesame seeds*
• ▢ Flaky sea salt
• ▢ 1/2 cup fresh cilantro leaves
• ▢ Lime zest
• ▢ Optional: vegan furikake or gomasio

Instructions

• Preheat the oven to 375°F/190°C.
• Lightly slash or prick the sweet potatoes several times with a sharp knife to allow for even ventilation. Place the potatoes on a parchment paper lined baking sheet, or directly on the oven rack. Bake for 75 minutes for medium-sized potatoes (60 minutes for small Japanese sweet potatoes; 85-90 minutes for large ones). Turn off the oven and keep the potatoes in the oven, with the door closed for 45 to 60 minutes.
• Meanwhile, make the Miso Tahini Butter. Add the softened vegan butter to a medium bowl, along with the tahini, miso paste, lime zest, lime juice, toasted sesame oil, agave, and red pepper flakes. Use a fork or whisk and mash until the mixture is very smooth. Taste for seasonings, and add the additional miso for more umami, lime juice for acidity, or sesame oil for toasted nutty flavor, as needed. If the butter is more on the melty side rather than creamed, pop it in the fridge for 20ish minutes until it reaches a spreadable consistency.
• Once the sweet potatoes are done, slice them open and spread the miso butter tahini on top. Sprinkle with the toasted sesame seeds and a pinch or two of flaky sea salt. Top with fresh cilantro leaves. Zest a bit of lime on top before serving. If desired, sprinkle some vegan furikake or gomasio on top before serving.

Notes

* To toast sesame seeds, add the seeds to a skillet over medium heat and toss occasionally until lightly golden, 3-5 minutes.

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Nutrition Info

Calories: 378kcal | Carbohydrates: 51g | Protein: 6g | Fat: 18g | Saturated Fat: 4g | Polyunsaturated Fat: 6g | Monounsaturated Fat: 7g | Trans Fat: 1g | Sodium: 410mg | Potassium: 848mg | Fiber: 8g | Sugar: 11g | Vitamin A: 32995IU | Vitamin C: 11mg | Calcium: 105mg | Iron: 2mg