Bring pot of water to boil. Add pasta and cook according to package directions. (we like al dente). Reserve 1 cup of pasta water for the sauce.
Meanwhile, season your shrimp with lemon pepper seasoning. In large skillet, melt 2 tbsp butter over medium heat. Add shrimp and cook until pink, 1 - 2 minutes per side*. Remove from pan and set aside.
Into the skillet, add the remaining butter and the garlic. Cook over medium-high heat until garlic is fragrant, about 1 minute. Whisk in flour and cook 2 - 3 minutes until flour is no longer raw. Whisk in cream, milk, lemon juice and chives. Bring sauce to a simmer, reduce heat and stir in parmesan cheese. Continue stirring until cheese is melted and the sauce begins to thicken.
Drain cooked pasta and add to the pan. Toss to coat with sauce. If sauce is too thick, thin with a splash of reserved pasta water. Add shrimp and toss gently to combine. Garnish with fresh parsley and serve with additional parmesan cheese and lemon slices.
Cook the shrimp until it's just done, otherwise the shrimp will get tough and chewy. Once the shrimp is opaque, remove it promptly from the pan so it stops cooking.I used jumbo shrimp to make this recipe and cooked the shrimp about 1-1/2 minutes per side. Cooking time will vary depending on the size of the shrimp you are using. Start with 1 minute per side and go from there.