2 medium onions, chopped
1/4 lb. margarine ( 1 stick)
2 cans (6 1/2 oz.) tuna, drained
2 C shredded cheddar cheese
1 C Bisquick
1 1/4 C milk
1/8 tsp pepper
1/4 tsp salt
2 tomatoes, thinly sliced
Heat oven to 400º. Grease square baking dish.
Cook onions and margarine in a 10 inch skillet, over low heat, until onions are light brown.
Sprinkle tuna, 1 C cheese and onions in casserole.
Beat Bisquick, milk, salt, pepper, and eggs until almost smooth (1 minute). Pour over casserole.
Bake until knife inserted in center comes out clean, about 25 - 30 minutes.
Top with tomatoes and remaining cheese. Bake until cheese is melted, 3 - 5 minutes.
Cool 5 minutes.
If desired, your favorite fish spice may be added to Bisquick mixture such as 1/2 tsp thyme or oregano.