Spinach Pesto

Toast the nuts: Heat a large dry frying pan over medium-low heat. Once hot, add the walnuts and toss from time to time, until they smell nutty and are darker by a few shades, 4 to 5 minutes (see Note 3).
Add the toasted nuts and garlic to a food processor. Blend until you have a fine crumb (but not a paste). Add the spinach and basil, pressing down as needed to fit. Blend until you have a coarse paste, scraping down the sides as needed.
NOTE: If your food processor is smaller, do this in two batches.
Add the lemon zest, 4 tablespoons (60 mL) lemon juice, 1 teaspoon kosher salt (or half amount sea salt), a few cracks of black pepper, chili flakes if using, and nutritional yeast.
Blend until a paste forms, scraping down the sides as you go. With the motor running, stream in the extra virgin olive oil until it forms a thick sauce.
If using, add in the capers and pulse a few times to incorporate.
Taste, adding more salt or lemon juice as needed. If your basil isn’t the best quality, you may need to add a pinch of sugar.
NOTE: the consistency may be a bit thicker and creamier than classic pesto.
Store pesto in a large sealed jar in the fridge for about 1 week. Or, freeze in ice cube trays; once set, transfer to a freezer-safe bag and freeze for 3 to 4 months.