An easy one this;
400g chopped tomatoes (if you are using fresh you will need to skin and deseed them)
1 medium onion - peeled
2-3 gloves of garlic – or more or less if you prefer
2 tbsp olive oil
1-2 tsp dried basil or/and oregano
Cut the onion into a small dice. Crush the garlic or chop into small slices. Heat oil in saucepan or deep sided frying pan and add the onion and garlic. Keep the heat low to medium and cook until the onions and are garlic are cooked but not brown. Add in the tomatoes and the dried basil, bring to a boil and reduce to a simmer for about 10-15 minutes until it thickens, don't forget to stir it.
Tip over cooked pasta and enjoy.
NB If you would like a thicker sauce you can add a tablespoon of tomato puree and you can make bigger batches and keep it in the fridge or even freeze it.