Preheat the oven to 425°F (218°C) and line two large baking sheets with parchment paper.
Spread the onion, tomatoes, veggies, and chickpeas evenly across the baking sheets. Drizzle with 2 Tbsp oil and sprinkle with 1/4 tsp salt and pepper (per sheet).
Roast the veggies for 18-23 minutes, or until they are slightly browned and juicy. The tomatoes should start to burst for optimal flavor.
Meanwhile, bring 3 quarts of salted water to a boil and cook the pasta until al dente according to the package directions. Reserve 1 cup of pasta water before draining.
Return the empty pot to low heat, add the remaining 1 Tbsp oil, minced garlic, and lemon zest. Cook until fragrant (30-60 seconds).
Add the drained pasta back to the pot along with 1/2 cup pasta water and the vegan parmesan. Toss until well coated, adding more pasta water as needed for a creamy consistency.
Gently fold in the roasted vegetables. Taste and adjust, adding more vegan parmesan, salt, or pepper as needed.
Serve immediately, garnished with fresh basil, red pepper flakes, and extra parmesan if desired.
Store leftovers in a covered container in the refrigerator for up to 3 days. Reheat with a splash of water to restore creaminess.