Prepare the dough
Pour all the ingredients in the bowl of the kitchen robot and mix 3 min, or 6 min by hand.
Shape a ball with the dough. Cover wih a humid towel and leave it for 10 min.
Prepare the topping
Cook the onions in the pan with a tablespoon of olive oil, until they get transparent. Add the carrots purée still frozen, and let it melt under cover. Add the balsamic vinegar, add salt and pepper.
Preheat the oven at 180°C.
Work the dough again during 1 min and divide it in two pieces. Take two baking papers and put one ball slightly flatened on one sheet, put the other sheet on top, flatened with a rolling pin. Do the same with the other ball. Leave it for 5 min.
Prick the dough with a fork and apply oil. Bake them covered with baking paper for 5 min.
Drain the tuna and crumble it. Spread the sauce on the discs. cover with tuna, minced olives and capers. Add salt, pepper and herbs.
Bake again for 30 min.
Serve hot with a green salad.
Put some chili pepper in the sauce!