Put the spaghetti in a sauce pan and bring to the boil, if you want it al dente, boil it for about 12 minutes.
As the spaghetti boils get started on the sauce. Chop and onion, and fry it of in a frying pan with oil. After they have gone golden brown, mince the garlic clove fry it all together along with the chilli flakes for about a minute.
Now add the chopped tomatoes and the tomato purée. Then add the juice of half a lime. Cut up the mozzarella into small pieces abd put in the pan and allow it to melt. Hen give the sauce a stir and allow to simmer for 4 minutes.
Strain the spaghetti and set aside.
Add the crayfish to the sauce and stir in. Add some salt and pepper.
Pour it onto the speghetti and your meal is finished!