Wash, clean, quarter and seed the tomatoes. Cut the flesh into small cubes. Peel and finely dice onion. Wash basil, cut into strips. Heat 3 tablespoons of olive oil in a pan.
Fry the pine nuts, onion and diced tomatoes over a high heat for 2-3 minutes. Season with salt, pepper and basil. Clean, clean and slice the mushrooms. Cut olives into fine slices.
Heat 2 tablespoons of olive oil. Fry the mushrooms on a high heat for 2-3 minutes. Season with salt and pepper. Douse with white wine, stir in sage leaves and olive rings. Wash and chop thyme and rocket.
Peel the red onion and cut into fine slices. Drain the tuna. Mix thyme, rocket, onion wedges and drained tuna. Season with salt, pepper and lemon juice. Cut the ciabatta into approx. 12 thick slices and place them on a baking tray.
Peel the garlic and press it through a garlic press. Mix with 4 tablespoons of olive oil. Drizzle evenly onto the slices of bread. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 5-8 minutes until golden brown.
Spread prepared toppings on top and serve.