Bring salted pot of water to boil and heat pan over medium heat.
Once water is boiling add pasta and cook until al dente. Reserve ½ cup of pasta water.
While pasta is cooking, heat pan over medium heat and melt butter and olive oil. Once bubbling, sauté garlic until fragrant. (If you want the pasta spicy , add red pepper now).
Add shrimp to pan and cook 3 minutes on one side, then flip and cook other side for 2 minutes, ensuring the shrimp is pink and cooked through. Season with salt and red pepper flakes.
Once shrimp is done cooking, turn off heat and add lemon juice and parsley and ensure it’s to your taste.
Once pasta is al dente, drain and add to pan. Slowly add pasta water, starting with a ¼ cup and turn heat back on.
Toss pasta in pan until pasta water thickens and emulsifies the sauce. Top with a little Parmesan or a touch of truffle oil if desired.