Bring a large pot of salted water to a rolling boil. Add the linguine and cook according to package directions until al dente. Reserve 1 cup of pasta water before draining.

While the pasta cooks, pat the peeled and deveined shrimp dry with paper towels. Season with salt and black pepper.

In a large skillet over medium-high heat, melt 2 tablespoons of unsalted butter with 2 tablespoons of olive oil. Add the seasoned shrimp in a single layer (cook in batches if necessary to avoid overcrowding). Cook for 1-2 minutes per side, until pink and opaque. Remove the shrimp from the skillet and set aside.

Reduce heat to medium. Add the remaining 4 tablespoons of butter to the same skillet. Once melted, add the minced garlic and red pepper flakes. Sauté for 30-60 seconds until fragrant, being careful not to burn the garlic.

Pour in the dry white wine (if using) and chicken broth. Bring to a gentle simmer, scraping up any browned bits from the bottom of the pan. Let it simmer for 2-3 minutes to reduce slightly.

Stir in the fresh lemon juice and the reserved pasta water (start with 1/2 cup, add more if needed).

Add the cooked shrimp back into the skillet with the sauce. Toss to coat.

Add the drained linguine directly to the skillet with the shrimp and sauce. Toss everything together, ensuring the pasta is well coated.

Stir in the fresh chopped parsley and 2 tablespoons of grated Parmesan cheese (if using). If the sauce seems too thick, add more reserved pasta water a tablespoon at a time until desired consistency is reached.

Serve immediately, garnished with extra fresh parsley and a sprinkle of Parmesan cheese, if desired.