Cook pasta according to package directions. Reserve 1 cup of pasta water before draining.
While pasta is cooking, heat olive oil in a large skillet over medium heat. Add garlic and red pepper flakes (if using) and cook for 1 minute, until fragrant.
Add broccoli, asparagus, carrots, and peas to the skillet and cook for 5-7 minutes, until tender-crisp.
Add the cooked pasta to the skillet with the vegetables. Toss to combine.
Add 0.5 cup of the reserved pasta water to the skillet and toss again. Add more pasta water as needed to create a light sauce.
Season with salt and pepper to taste. Serve immediately, topped with grated Parmesan cheese.
Notes
Feel free to add other vegetables like zucchini or bell peppers. A squeeze of lemon juice can brighten the flavors even more.