Step 1: Bring a large pot of salted water to a boil and cook the pasta according to package directions until just shy of al dente.
Step 2: While the pasta is cooking, reserve 1 cup of the pasta water, then drain the noodles.
Step 3: In a large skillet, heat the butter and olive oil over medium heat. Add the minced garlic and red pepper flakes, sautéing for 1-2 minutes until fragrant and golden.
Step 4: Stir in the lemon zest and lemon juice into the garlic butter mixture.
Step 5: Add the cooked pasta to the skillet along with 1/2 cup of the reserved pasta water. Toss continuously for 2 minutes over medium heat to create a silky sauce.
Step 6: Remove from heat, stir in the Parmesan cheese and fresh parsley, and season with salt and pepper. Add more pasta water if the easy lemon garlic pasta needs more moisture.