Mix lemon juice, salt and pepper, fold in oil. Peel garlic and chop finely. Wash and pluck the basil and cut into strips. Add garlic to the marinade
Drain the tuna and finely pluck with a fork. Mix the tuna with the basil marinade. Leave to stand for at least 20 minutes
Toast bread. Spread the tuna fish on top. Arrange crostini on salad leaves. Garnish with tomato quarters, lemon slices and basil
Ciabatta is an Italian white bread, which you can get fresh at the baker's or packed for ready baking in the bread shelf. Alternatively, you can use baguette, bread by the meter or normal white bread. You can prepare the tuna well and later arrange it on the bread slices