Eating In

800g good, tinned Italian plum tomatoes
2 tbsp olive oil
1 small onion, finely chopped
2 garlic cloves, crushed
1 tsp sugar
Dash of red-wine vinegar
3 stems of fresh basil
Extra-virgin oil, to serve (optional)

Heat the oil in a medium saucepan on a medium-low heat and add the chopped onion. Soften for about five to seven minutes, until translucent but not coloured. Stir in the garlic and cook for another two minutes.
Tip in the tomatoes, and break up with a wooden spoon, if necessary, then add the sugar, vinegar and the stems of the basil, reserving the leaves. Season lightly. Bring to a simmer, then turn down the heat and simmer for 45 minutes, stirring occasionally, until thick.
Test the seasoning, add the basil leaves, roughly torn, and drizzle in a little extra-virgin olive oil if you like before serving.