1. Bring a large pot of water to the boil and salt it generously. Cook the spaghetti to al dente.
2. While the spaghetti is cooking, heat a very large frying pan over medium heat and add the olive oil and onion. Fry the onion for a few minutes, then add the garlic. When the garlic starts to brown, add the tomato paste and anchovies (if using) and cook for about 2 minutes to get the raw taste out of the paste. Add the prawn meat and toss for about 2 minutes, until just cooked. Add the cooked pasta into the prawn mixture along with about 2 tablespoons of the pasta water. Toss to mix, then toss through the basil and parsley and serve.
Serve with: Adam Liaw's easy berry Chantilly cake
Find more of Adam Liaw's recipes in the Good Food New Classics cookbook.