Cook the spaghetti in a large pan of boiling water for about 10 minutes or until al dente (tender but still firm to the bite), stirring occasionally.
Drain the spaghetti in a colander, reserving a little of the cooking water.
Heat the oil in a large frying pan, add the garlic and chilli flakes and cook for 1min. Add the spaghetti, reserved cooking water and chopped tomatoes and stir to mix well. Simmer for 10min.
Meanwhile, heat a separate large frying pan over medium heat and add the sardines, olives and capers. Stir the ingredients together and cook for 3min.
Stir the sauce through the spaghetti. Serve the spaghetti sardines warm.
Serving Suggestions: Serve the spaghetti sardines over a bed of lightly steamed greens. A pot of crusty garlic bread on the side is essential.