Prepare onion, garlic, tomato purée, herbs, opened tomatoes and grated cheese before the sausages leave their packet. This contains the raw-meat stage and prevents contaminated hands from touching tins, drawers and the grater.
Use a separate board for sausages and let an adult make even slices. Put them straight into the cold non-stick pan, then wash hands and clean the board, knife, tap and any touched surface. Starting the pan cold gives sausage fat time to release.
Cook slowly and turn the rounds so both cut faces meet the pan. Browning outside does not prove the middle is safe, so cut into a thick piece before adding tomato ingredients. It should be steaming throughout without pink or red meat.
Add onion and garlic while the sausage continues cooking, lowering the heat if the garlic catches. Stir tomato purée around the hot pan for one minute before adding chopped tomatoes; this removes its raw metallic edge and lifts the browned flavour from the base.
Simmer the sauce uncovered until a spoon leaves a short trail through it. If it is still watery when pasta is ready, leave the pasta in its colander briefly and reduce the sauce; if it becomes too tight, add pasta water one tablespoon at a time.
Fold the pasta through rather than stirring hard enough to break the shapes. Heat until everything is steaming, then move the pan off the hob before the child adds grated cheese. Serve promptly and check hot sausage centres in child portions.