Slow-cooked courgette spaghetti

Halve the courgettes lengthways, then slice them as thinly as you can into half moons. In a large pan, heat half of the oil over a low-medium heat, then cook the onions for 10-15 minutes or until soft and browned – add a splash of water if the onions catch.

Add the courgettes and carrots, and cook over a medium-high heat for 10 minutes, stirring occasionally, until they collapse and catch a little colour. Lower the heat and cook for 30 minutes – it is fine if the courgettes catch slightly so that they caramelise, but scrape at the bottom of the pan from time to time, adding splashes of water to stop it burning. Add the tomato paste and cook for 2 minutes.

If using fresh tomatoes, cut them in half and grate coarsely, leaving the skins behind. Add the tomato pulp, sugar and garlic to the pan. Cook down the mixture over a medium-high heat for 30-40 minutes, stirring from time to time. Help the process along by gently crushing the vegetables with a masher. If it does get dry, add some splashes of water.

At this stage, season the mixture. When the paste starts spitting fervently, lower the heat. You should end up with a thick, deeply flavoured brown paste.

Pour the hot paste into a sterilised jar, cover with a lid and cool. You can pour a little oil on top of the paste to help it keep for longer, as well as some wax paper or kitchen paper. It will keep in the fridge for two months if covered with enough oil.

Cook the spaghetti in a large pan of lightly salted boiling water following pack instructions, drain well then stir through half of the warmed sauce. Divide into four bowls and scatter over the parmesan and basil.