tomato sauce with butter and onion

900g ripe tomatoes
75g butter
1 onion, peeled and halved
salt

Immerse the tomatoes for 1 minute in boiling water. Once cooled down, peel and chop them.
In a pot simmer tomatoes, butter, onion and salt with the lid open for about 45 minutes. Stir occasionally. Eventually the fat should have separated from the tomatoes.

Discard the onion. Add your pasta of choice or gnocchi to the tomato sauce, sprinkle with grated parmesan and serve immediately.