Start by sautéing the onion and garlic together with the olive oil for 2 minutes . Add in the pepper and zucchini , season with salt and pepper and fry for 2 minutes. Add in the tomato paste, cook for a minute then add in the tomato pulp with basil. Splash in a little water, olives and capers and cook gently for 10-15 minutes. When ready, turn off the heat and stir in the fresh mint. Meanwhile, cook the pasta in a pan of boiling water, and also season the tuna with salt and pepper and quickly pan-fry on both sides in a hot pan. To serve, mix the cooked pasta with the sauce, spoon into 2 plates and slice the tuna and place on top.