Cook the Pasta:

1. Boil the Water: Bring a large pot of salted water to a boil.
2. Cook the Pasta: Add the angel hair pasta and cook until al dente, according to package instructions (usually 3-4 minutes). Reserve 1 cup of pasta water, then drain the pasta and set aside.

Prepare the Scampi Sauce:

3. Heat the Pan: In a large skillet, heat the olive oil and 2 tablespoons of butter over medium heat.
4. Sauté Garlic: Add the minced garlic and red pepper flakes (if using) and sauté until fragrant, about 1-2 minutes.
5. Cook the Shrimp: Add the shrimp to the skillet, season with salt and pepper, and cook until pink and opaque, about 2-3 minutes per side. Remove the shrimp and set aside.

Build the Sauce:

6. Deglaze the Pan: Pour the white wine or chicken broth into the skillet, scraping up any browned bits from the bottom. Let it simmer for 2-3 minutes to reduce slightly.
7. Add Lemon: Stir in the lemon juice and zest, then return the shrimp to the skillet.

Combine and Serve:

8. Toss the Pasta: Add the cooked angel hair pasta to the skillet, along with the remaining 2 tablespoons of butter and chopped parsley. Toss to coat the pasta evenly in the sauce. If needed, add reserved pasta water a little at a time to loosen the sauce.
9. Garnish and Serve: Serve immediately, garnished with Parmesan cheese and additional parsley if desired.