Preheat the oven to 450°F/232°C. Line a rimmed baking sheet with parchment paper or drizzle with some oil to prevent the eggplant from sticking.
Prep the eggplant. Using a vegetable peeler, peel the eggplant in alternating strips from top to bottom (you can peel them entirely, but I like the zebra look). Slice the eggplants into 1 ½-inch (~4 cm) thick wedges and add to the baking sheet. Drizzle with the 2 tablespoons regular olive oil or avocado oil, a generous amount of salt, and black pepper to taste. Toss well and arrange the eggplant in a single layer.
Prep the garlic. Remove the outer layers of the garlic head and then slice off a thin layer off the top to expose the skin of the cloves. Rub the exposed cloves with a bit of olive oil. Wrap in aluminum foil to make a packet. Place the packet on the same baking sheet as the eggplant.
Roast the eggplant for 25-35 minutes, or until the eggplant is deeply golden brown on the outside yet very soft and tender, tossing halfway through.For skinnier, thin-skinned varieties of eggplant, roast 25 minutes.For larger eggplants roast for 25 minutes at 450°F, then turn the heat down to 400°F and roast for another 10 to 15 minutes.The garlic should also take 25 to 35 minutes to roast (the garlic is done when cloves are very soft and practically oozing out of their skins).
Meanwhile, cook the pasta. Bring a pot of generously salted water to boil and cook the pasta according to package directions until al dente, then drain.
Meanwhile, make the gremolata. Finely chop the parsley, then chop the thyme leaves and mix together. Using a microplane, zest the lemon directly on top of the herbs and then sprinkle with some sea salt or kosher salt and toss to combine.
Meanwhile, make the zucchini ribbons. Using a Y-shaped vegetable peeler, shave the zucchini lengthwise in a downwards motion to get wide vegetable ribbons. Once you get to the core, it will be hard to continue shaving. Save the core for another use, like stir-fries or freeze it for smoothies.
Make the roasted garlic dressing. When the garlic is done roasting and is cool enough to handle, squeeze the cloves into a small bowl. Mash with a fork, add in the lemon juice, and season to taste with salt and pepper. Whisk together, and then drizzle in the extra virgin olive oil and whisk until emulsified.
Assemble the pasta. Add the hot cooked pasta to a serving bowl and add the zucchini ribbons. Sprinkle with a couple pinches of salt and pepper, then dress with the roasted garlic dressing and toss to combine. Add the roasted eggplant, and toss to combine again. Top the eggplant pasta with the gremolata and toasted walnuts. Transfer to serving bowls and top each bowl with a drizzle of tahini, if desired.