Cook the tagliatelle in boiling water for 10 minutes, or until al dente. Drain and return to the pan.
Meanwhile, melt the butter in a frying pan and add the chilli, garlic and prawns and cook for 1-2 minutes to heat through.
Add to the tagliatelle, toss then stir in the fresh chives and lemon juice. Season to taste and serve in bowls or pasta dishes.
Cook's tip: Cooking pasta until "al dente" means that the pasta should be cooked through, but still have some bite. This ensures that the pasta holds it shape and has a firm texture to hold sauces and accompaniments.