1. Ask your butcher to pound the meat well to thin it out. Dredge the fillets in flour and shake off any excess. Pour olive oil into a medium saucepan and sauté half of the fillets. Turn them to brown evenly all over. Remove them from the pan and place them in a glass bowl. Repeat the process with the remaining fillets.
2. Add the onion and garlic to the pan and sauté. Add the small mushrooms, stir, and return the fillets to the saucepan. Season with salt and pepper and add enough water to cover the fillets. Lower the heat and simmer until the fillets are cooked through.
3. Toast the sliced bread and top it with the fillets and mushrooms. If you like, garnish with a little parsley and serve.
