Add the spaghetti and allow to cook until al dente according to package instructions, approximately 9 minutes.
Place the peeled and deveined shrimp in a medium bowl.
Add a few tablespoons of olive oil and season generously with salt and pepper. heat a large skillet or frying pan over medium high heat then add the shrimp, in batches if necessary, and allow to sear for a minute per side until golden then remove and set aside.
In the same pan, add another tablespoon of olive oil then stir in the fresh minced garlic, lemon zest, finely chopped chillies and parsley.
Cook for 30 seconds then add a ladle full of the pasta's cooking water (white wine can also be used) and a generous squeeze of lemon juice. Season with salt and pepper.
Drain the pasta, reserving a cup of cooking water, then add the shrimp and cooked pasta back to the pasta sauce.
Toss to coat, adding a splash of pasta water, if necessary.
Taste and adjust seasoning if necessary. Serve with extra parsley and lemon for squeezing.