There are many different types of steamers. Examples include pasta cookers, stackable steamers, collapsible steamer baskets, fish poachers and even a simple device like a roasting pan with a rack.
The roasting pan is good for holding larger quantities of food. Cover the bottom of the pan with water, and place two used tuna cans in the pan. Place the rack that came with the roster on the tuna cans, and place the items to be cooked on the rack. Put the pan over two burners on the stove and steam the food. A whole fish should take about 15 to 20 minutes to steam.