1. Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Reserve 1 cup of pasta water, then drain and set aside.
2. In a large skillet over medium heat, melt 2 tablespoons of butter. Add the shrimp and season with salt and pepper. Cook for 2-3 minutes on each side until pink and opaque. Remove from the skillet and set aside.
3. In the same skillet, melt the remaining 2 tablespoons of butter. Add the minced garlic and red pepper flakes (if using) and sauté for about 1 minute, until fragrant.
4. Pour in the white wine or chicken broth, scraping up any brown bits from the bottom of the skillet. Let it simmer for 2-3 minutes until reduced slightly.
5. Add the cooked pasta to the skillet along with the shrimp. Toss to combine, adding reserved pasta water as needed to reach your desired consistency.
6. Stir in the lemon juice, chopped parsley, and grated Parmesan cheese. Season with additional salt and pepper to taste.
7. Serve immediately, garnishing with extra parsley and Parmesan if desired.

Cooking this dish always reminds me of the patience and confidence I gained from watching my abuela. She taught me the importance of tasting as you go and trusting your senses, a lesson I carry into every meal I create.