Start by bringing a large pot of salted water to a rolling boil. Once boiling, add the penne pasta, stirring gently. Cook for about 8-10 minutes until al dente. Before draining, reserve 1/2 cup of pasta water. Drain and set aside.

In a deep skillet, heat 2 tablespoons of olive oil over medium-high heat. Add the chopped red onion and carrot, and sauté for 2 minutes until softened.

Add the broccoli florets and sliced bell pepper to the skillet. Continue sautéing for another 2 minutes until the vegetables are bright and just tender.

Stir in the diced squash and zucchini, and cook for an additional 2-3 minutes until they are tender-crisp.

Add minced garlic, halved cherry tomatoes, and Italian seasoning to the skillet. Cook for another 2 minutes until fragrant.

Mix the sautéed vegetables into the pasta pot with the drained penne. Drizzle with lemon juice and combine thoroughly.

Gradually add the reserved pasta water until you reach the desired sauce consistency. Toss in grated Parmesan cheese and mix well.

Portion onto plates or into bowls, sprinkle with remaining Parmesan and fresh parsley, and serve immediately while warm.