Bring a large pot of salted water to a rolling boil. Cook pasta according to package directions until al dente, usually 8-10 minutes. Before draining, reserve 1 cup of pasta water for later use. Drain pasta but don't rinse.
While the pasta cooks, prepare your vegetable medley, ensuring uniform sizes for even cooking.
Heat olive oil in a large skillet over medium heat. Add minced garlic and sauté for 30 seconds until fragrant but not browned.
Add vegetables in order of cooking time: first the bell peppers, cooking for 2 minutes, then add zucchini and yellow squash for another 2 minutes. Finally, add asparagus, broccoli, and peas, cooking for 3-4 minutes until bright and just crisp-tender.
Add the cooked pasta to the vegetable mixture along with cherry tomatoes and half of the fresh herbs. Toss everything together, adding reserved pasta water a little at a time to create a light sauce.
Sprinkle with Parmesan cheese, drizzle with lemon juice, and season with salt and pepper to taste.
Transfer to a large serving platter. Garnish with remaining fresh herbs, additional Parmesan if desired, and optional red pepper flakes. Serve immediately.