In a large pot of salted boiling water, cook the linguine according to the package directions until al dente. Drain and set aside, reserving a cup of pasta water.
While the pasta cooks, pat the shrimp dry with paper towels and season with salt and black pepper.
In a large skillet over medium heat, melt 2 tablespoons of butter. Add the minced garlic and red pepper flakes, cooking for about 1 minute until fragrant, being careful not to burn the garlic.
Add the seasoned shrimp to the skillet. Cook for about 2-3 minutes on one side until pink, then flip over and add the lemon juice and zest. Cook for another 2-3 minutes until fully cooked through. Remove the shrimp from the skillet and set aside.
In the same skillet, pour in the chicken broth and bring to a simmer. Let it reduce slightly for about 2 minutes. Stir in the remaining butter and mix until melted and well combined.
Add the cooked linguine to the skillet, tossing to coat in the garlic butter sauce. If the pasta seems dry, add reserved pasta water a little at a time until you reach desired consistency. Stir in the cooked shrimp and half of the fresh parsley.
Plate the shrimp linguine in bowls and garnish with the remaining parsley and grated Parmesan cheese if using.
Notes
Serve with wedges of lemon on the side and a sprinkle of additional parsley for a fresh look.