Start by gathering and prepping all your ingredients. Chop the vegetables into bite-sized pieces and measure out the pasta.

Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente, around 8-10 minutes, reserving a cup of the cooking water before draining.

While the pasta cooks, heat olive oil in a large skillet over medium heat. Add the minced garlic and cook until fragrant, about 30 seconds.

Toss in the sliced red onions, carrots, and broccoli. Sauté for 5-7 minutes until tender.

Add the sliced bell peppers and zucchini into the skillet. Season with salt, black pepper, Italian seasoning, and optional red pepper flakes. Sauté for another 3-5 minutes until the vegetables are crisp-tender.

Add a few tablespoons of the reserved pasta water to the vegetable mixture to create a silky sauce. Stir to combine.

Once the pasta is cooked and drained, add it to the skillet with the sautéed vegetables. Toss everything together until well coated.

Stir in the grated Parmesan cheese and lemon juice, mixing until the cheese melts.

Taste and adjust seasoning, adding more salt or pepper as needed.

Garnish with fresh basil or parsley before serving.