Cook pasta in boiling, salted water, until al dente, if serving hot or just firm to the bite if serving as a salad.
While pasta is cooking, combine prawns, garlic, onion, chilli flakes, lemon juice, oil, tomatoes and basil in a bowl.
Return pasta with prawn and tomato mixture to the warm pasta pot.
Toss well to coat.
Add salt and pepper to taste.
Serve immediately or at room temperature.