Make the roasted vegetables. Preheat the oven to 400F. Toss the vegetables (zucchini, mushrooms, bell pepper and tomatoes) with olive oil and a generous pinch of salt and pepper. Spread into a baking sheet and roast until tender, about 20-25 minutes.
Make the vegan pesto. Place the basil, pine nuts, garlic, lemon juice, nutritional yeast and salt into the base of a food processor. Pulse until mostly chopped, then with the motor running, drizzle in the olive oil until a chunky pesto forms. Season to taste, adding more salt as desired.
Make the pasta. Heat a large pot of salted water to a boil. Add the rigatoni and cook until al dente, according to package directions. Drain, reserving 1/4 cup pasta water.
Assemble! Toss the pasta with prepared pesto and roasted vegetables. If needed, add in a tablespoon or two of pasta water to help combine.