Heat olive oil in large skillet or pan over medium-high heat. Pat shrimp dry with paper towels, then season with salt and pepper. Pan sear shrimp, about 2 minutes per side. Remove shrimp and set aside.

Start bringing a pot of water for pasta to boil and salt generously. In the same pan used to cook shrimp, add onion to remaining oil and cook until softened, about 3 minutes. Add garlic and red pepper flakes, cook for 30 seconds or until fragrant.

Add capers and tomatoes, then cook for about 2 minutes or until tomatoes begin to soften. Add lemon zest, lemon juice, white wine, and chicken broth, then bring to rolling simmer while scraping brown bits from bottom of pan. Add pasta to seasoned boiling water and cook for ½ directed time on packaging.

Continue simmering vegetables in wine and broth while pasta cooks. Once pasta is ½ cooked, add it to simmering pan directly from pasta water and allow to simmer for second ½ of cooking time or until al dente.

Turn off heat. Add butter and stir in until completely melted. Add shrimp back to pan and stir in until warmed. Serve topped with grated parmesan and chopped parsley.