Warm a large, deep frying pan on the hob and add the oil.
Chop the onion, celery, carrot and courgette if using and add to the pan. Stir and leave to cook on a low heat for 10 minutes with the lid on.
Add the garlic and fry for a couple of minutes. Wash the lentils in a sieve under cold water until the water runs clear and add to the pan, stir before adding all of the rest of the ingredients apart from the basil and salt and pepper.
Put on the lid and leave to simmer on a low heat until the lentils have soaked up all the liquid (approximately 30 minutes).
If serving with pasta, allow 100g per adult / 50g per child and cook as per the packet instructions.
Before serving, tear and stir in most of the basil leaves and season to taste with salt and pepper. Add the nutritional yeast now if you want to. If you'd like to give the sauce a bit of a kick you could also add some cayenne pepper.
Enjoy!
Store in the fridge for up to a week and in the freezer for up to six months.
