Bring a pot of water to a boil and add 2 tablespoons salt . Add the spaghetti, give it a stir and cook until al dente according to the package instructions.
Meanwhile, heat a large saute pan over medium heat. Add the oil, butter, garlic and a pinch of salt and sweat the garlic for 2 minutes. Add the shrimp, season with salt and pepper and cook, stirring, 1 minute. Add the wine, lemon juice and chile flakes if using and cook until the shrimp are just cooked through, 3 to 5 minutes.
Reserve some of the pasta water, then drain the spaghetti. Add the spaghetti and a little of the reserved pasta water to the pan with the shrimp and toss to combine. Toss in the parsley if using and serve.
For more ingredient substitution ideas, see the article below.