Cook pasta in well-salted water until al dente. Reserve 1/2 cup pasta water, then drain.

Heat olive oil in a large skillet over medium heat. Add the red onion and bell pepper. Season with salt and pepper and cook for 3–4 minutes.

Add the diced zucchini and cook another 3–4 minutes, until the vegetables are softened and lightly golden.

Add the cherry tomatoes and cook for 2–3 minutes, just until they start to blister and release some of their juices.

Add the garlic and red pepper flakes and cook for 30 seconds.

Lower the heat and add the heavy cream. Stir and let it gently simmer for 1–2 minutes.

Stir in the pesto and Parmesan. Add the pasta and toss until coated, adding pasta water a little at a time until the sauce is silky and creamy.

Finish with extra Parmesan, cracked black pepper, and a little drizzle of pesto.