In a large pot, bring salted water to a rolling boil. Add pasta and cook for about 8-10 minutes until al dente. Reserve 1/2 cup pasta water, then drain.

In a large skillet, heat olive oil over medium-high heat. Add red onion and carrots and sauté for about 2 minutes until onion is translucent.

Stir in broccoli and bell pepper. Sauté for an additional 2 minutes until vegetables are tender but crisp.

Add zucchini and squash, and cook for 2-3 minutes until softened but still slightly firm.

Lower heat and add garlic and cherry tomatoes. Sauté for 2 minutes until garlic is fragrant and tomatoes are juicy.

Transfer the vegetables to the pot with the drained pasta. Toss to coat evenly.

Drizzle with lemon juice and stir in reserved pasta water until you reach desired sauciness.

Mix in Parmesan cheese and parsley. Serve warm.