Boil the pasta: Bring a large pot of salted water to a rolling boil.
Add pasta and cook until just shy of al dente. Reserve 1 cup of the starchy water, then drain.
Prep the veggies: While the pasta cooks, slice your vegetables into bite-sized pieces so they cook quickly and evenly.
Start the aromatics: In a large skillet, warm the olive oil over medium heat. Add the garlic and red pepper flakes.
Cook 30–60 seconds until fragrant—don’t brown the garlic.
Sauté the hearty veggies first: Add veggies that need longer (onion, broccoli, peppers, mushrooms). Season with salt and cook 4–6 minutes, stirring.
Add tender veggies: Stir in quick-cooking options (zucchini, tomatoes, peas, spinach). Cook another 2–4 minutes until tender but bright.
Build the sauce: Add a splash of the reserved pasta water to the skillet and scrape up any flavorful bits.
Add lemon zest and a squeeze of lemon juice.
Toss with pasta: Add the drained pasta to the skillet. Toss well with tongs, adding more reserved water a little at a time until the pasta looks glossy and coated.
Finish and season: Stir in cheese (if using) and herbs. Taste and adjust with more salt, pepper, or lemon.
Serve: Divide into bowls and top with a drizzle of olive oil and extra cheese if you like.