Remove the stalk and cut a shallow cross at the base of tomato. Plunge the tomatoes into boiling water for 15 seconds, and then transfer them into a bowl of iced water. Peel the skin away and dice.
Heat the olive oil in a saucepan and gently cook the chopped shallot and garlic until softened. Stir in the diced tomatoes, tomato paste, chilli flakes, balsamic vinegar and sugar. Bring to a simmer and cook slowly for 30 minutes. Stir in the basil and season with salt and pepper. Serve with hot cooked pasta. Store the rest in a clean box in the fridge for up to a week or so.