Bring a large pot of salted water to a boil, then add the pasta and cook until just al dente, about 8 minutes. Drain, toss with a little olive oil to prevent sticking, and set aside.
While the pasta cooks, heat a large skillet over medium heat and add 2 tablespoons of olive oil. Once shimmering, add the minced garlic and sauté until fragrant, about 30 seconds, smelling slightly nutty and golden.
Add the sliced bell peppers and zucchini to the skillet. Cook, stirring often, until vegetables are crisp-tender and slightly caramelized, about 3-4 minutes. They should smell fresh and look vibrant.
Push the vegetables to the side of the skillet and add the shrimp. Cook until pink and opaque, about 2-3 minutes per side, until they have a slight bounce when pressed. Season with salt, pepper, and red pepper flakes if using.
Add the halved cherry tomatoes, lemon zest, and a squeeze of lemon juice to the pan. Stir everything together and cook for 1-2 minutes, just enough for the tomatoes to soften and release their juices.
Pour the cooked pasta into the skillet with the vegetables and shrimp. Toss everything gently, adding reserved pasta water a little at a time until the mixture is glossy and well-coated. The sauce should shimmer and smell citrusy and fresh.
Taste and adjust seasoning with additional salt, pepper, and lemon juice if needed. Remove from heat.
Serve immediately, garnished with chopped fresh basil and grated Parmesan cheese, if desired. The dish should be hot, vibrant, and bursting with fresh flavors, perfect for a lively dinner.
