1: Heat the olive oil in a saucepan over a medium heat.
Once hot, add the crushed garlic cloves and cook until golden (roughly five minutes).
2: Stir in the tomato purée with a wooden spoon.
Add the chopped tomatoes and crush them with a potato masher (or a large fork). Add the salt, sugar, pepper and basil and stir. Simmer over a low heat until the sauce has reduced by a third (roughly 30 minutes).
3: Remove the pan from the heat and let cool slightly.
Transfer to a sealed container, store in the fridge and allow it to cool completely. Before serving, remove the basil and chopped garlic, and transfer the sauce to a small dipping bowl. Serve cold or warm. To warm, heat in the microwave for one minute in a microwave-safe container, stirring halfway through.