On Saturdays, I buy my fish from a stall in the farmers' market, where I enjoy going early in the morning in order to get the best choice. Yesterday the fish looked wonderful so I decided to make a fish soup, a simple and quick one with a mixed of firm-flesh fishes plus few prawns. I picked up a wild sea bream and two mullets the fishmonger cleaned for me and I kept the bones and the heads for the stock.