Bring a large pot of water with 1 Tbsp of salt added to a boil. Once boiling, add the pasta and cook until al dente (different kinds vary so go according to package directions). Reserve 1/4 cup of the pasta water then drain the remaining water. Toss noodles with 1 tsp olive oil to prevent sticking and set aside.

Meanwhile, heat 2 tsp of olive oil in a large skillet over medium heat. Add the shallot and cook for a minute then add the garlic and cook for another minute or until fragrant. Add the shrimp and sprinkle with 1/2 tsp salt, 1/2 tsp black pepper and the red pepper flakes (if using). Cook, stirring frequently, for 3-4 minutes or until shrimp is opaque. Transfer to a plate and set aside. 

Heat the remaining 1 Tbsp olive oil in the skillet over medium heat. Add the asparagus and the remaining 1/2 tsp salt and 1/2 tsp black pepper. Saute for 6-7 minutes or until asparagus is tender. Remove from heat. 

Add the cooked shrimp and pasta back to the skillet and toss with 2 Tbsp of the pasta water, lemon juice, lemon zest and fresh parsley. Add more of the pasta water if needed. Serve warm and sprinkle with freshly grated parmesan and more parsley to serve.