Rinse the peppers and tomatoes, dab dry and roast evenly on all sides on a grill or in a frying pan without fat. Remove the skin, remove the seeds and crush coarsely with a fork. Peel the garlic cloves, fry, crush and mix in. Mix in the juice of one lemon, oil, cumin and salt.
Portion onto plates and garnish with tuna, olives and capers.