Preheat oven to 425°F.

Arrange mushrooms, onion and garlic in a single layer on a large, rimmed baking sheet. Drizzle with oil and season with salt and pepper. Toss well to coat and spread it all back into a single layer. Roast until the mushrooms are golden brown, about 30 minutes.

While mushrooms are roasting, toast pine nuts in a small skillet until golden. Remove from heat. Place kale, garlic, salt, red pepper flakes, nutritional yeast and toasted pine nuts in a food processor and pulse until finely chopped. Slowly stream in the oil while the motor is running until smooth, scraping down the sides as needed.

Cook the pasta according to package instructions, reserving 1 cup of the cooking liquid before draining. Return cooked pasta to the pot, add pesto and as much of the reserved cooking liquid as you need to make it nice and saucy.

To serve, divide the pasta between 4 bowls. Top each portion with some of the roasted veggies, season with salt if needed, and enjoy!