Combine water, oil and salt and bring it to boil. Put the spaghetti on the boiling water. Cook until al dente. Reserve 1/4 cup pasta water.

Heat olive oil in a pan and add garlic. Saute the garlic on a low heat until fragrant. Add shrimp and chili flakes. Cook the shrimp for 3-4 minutes. Add ⅛ cup pasta water to the pan and bring to a boil. Add parsley.

When the pasta water has reduced a little and thickened into a sauce (about 2 minutes), add the drained pasta and toss in the sauce. Add the remaining pasta water

Add a pinch of salt to taste and parmesan cheese.

Squeeze lemon juice and mix everything. Serve immediately.