Bring a large pot of water to a boil, add 1 Tbsp salt and 1 Tbsp olive oil, and cook pasta according to package instructions until Al'dente, or desired doneness (meanwhile, continue with recipe). Drain pasta, return to pot, and cover to keep warm. Place a large, deep pan over medium/high heat and add 1 Tbsp olive oil and 1 Tbsp butter. Add asparagus, season lightly with 1/4 tsp salt and 1/8 tsp pepper, and cook uncovered for 5 minutes or until crisp-tender, stirring occasionally. Remove from pan. In the same hot skillet, add 2 Tbsp oil and 2 Tbsp butter. Once the butter is melted, add minced garlic and red pepper flakes if using, and sautee stirring frequently for 1 minute. Add shrimp in a single layer and season with 1 tsp salt and 1/4 tsp black pepper. Saute until shrimp are pink and not translucent (about 1 minute per side). Be careful not to overcook or the shrimp will be tough. Add lemon zest, juice, and parsley, and stir to combine. Turn off the heat and return the pasta and asparagus to the pan. Toss everything to combine and serve with freshly grated parmesan.