Peel onion and garlic and dice very finely. Drain the tuna and crush it finely with a fork. Stir in yoghurt, onion and garlic. Season to taste with salt, pepper and lime juice. Fold in capers
Wash the lime hot, dab dry and cut into thin slices. Cut the cold cuts in half and arrange them on top. Spread tuna cream over it. Wash, quarter and arrange the tomatoes. Garnish. Add bread
Tuna is not exactly a lean fish (average 15 g fat/100 g). Only the lean fillets migrate into the can. But only those in their own juice/natural (1 g fat/100 g) are low-fat. Preserved in oil, they have drained 10 g fat themselves.