Cook the Pasta: Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water before draining.
Sauté the Aromatics: In a large skillet, heat the olive oil over medium heat. Add the minced garlic and cook for 1-2 minutes until fragrant, stirring to prevent burning.
Add Veggies (Optional): If using cherry tomatoes and spinach, add them to the skillet. Cook for 2-3 minutes until the tomatoes soften and the spinach wilts slightly.
Make the Sauce: Lower the heat to medium-low and add the Boursin cheese to the skillet. Stir until it begins to melt. Gradually pour in the heavy cream, stirring constantly to create a smooth, creamy sauce. Add 1/4 to 1/2 cup of the reserved pasta water to adjust the sauce consistency.
Combine Pasta and Sauce: Add the drained pasta to the skillet and toss to coat evenly in the creamy Boursin sauce. If the sauce is too thick, add more pasta water, a tablespoon at a time.
Season and Finish: Stir in the grated Parmesan cheese and season with salt, black pepper, and red pepper flakes (if using). Taste and adjust seasoning as needed.
Serve: Divide the pasta among plates and garnish with fresh parsley or basil. Serve immediately with extra Parmesan on the side for sprinkling.