Step 1To make the sauce, heat oil in a non-stick pan and cook onion and garlic until softened. Add a little spray oil if necessary. Add chilli flakes and cook for a minute.
Step 2Add the passata and sugar and cook for 3-4 minutes. Add coconut milk, season with pepper and heat for 5 minutes, stirring a few times.
Step 3To cook the pasta, fill a large pot with water and bring to the boil. Add fettuccini and cook until al dente — about 3-4 minutes.
Step 4Remove from the heat. Drain almost all of the liquid, leaving about 1/4 cup water with the pasta. This will stop it sticking.
Step 5To cook the mussels add the liquid stock to a large pan and bring to the boil. Add mussels and steam until open. When opened remove from the heat. Throw out any that don’t open.
Step 6Remove cooked mussels from shells. Add the cooked fettuccini to the sauce. Stir to combine. Add mussels and serve. Garnish with fresh herbs and lemon.