Clean the gizzards well and put them to boil in a pressure cooker with 1 tablespoon vinegar for 20 minutes after the water comes to a boil. Fry the onion that you've cut into crescents, peel the potatoes and cut them in a pan.
Mix the onions and cooked gizzards with the potatoes. Season with salt and spices to taste. Top with beer and about 2/3 cup (150 ml) of water.
Put to bake for about 30 minutes in a moderately heated oven.