I must confess I am a Bisquick junkie...and this is my favourite baked meat sandwich. It came from a Bisquick cookbooklet c.1959 (from my dear mother's recipe collection)

(Bisquick biscuit recipe: add 2/3 cup milk to 2 cups Bisquick; Stir with fork into a soft dough.)

Heat oven to 400 degrees (mod. Hot). Cook pork or beef and onion over low heat until no longer pink. (Do not brown. Stir with fork to break up as it cooks.) Cool. Mix in rest of ingredients. Add 1/4 cup mayonnaise to Bisquick dough (see above). Mix well with fork. Spread half of dough in well greased square pan, 8x8x2". Spread meat mixture over dough. Spread rest of dough over mixture. (The top will even out during baking.) Brush with beaten egg yolk to give crusty glaze. Bake 25 to 30 minutes. Cut in slices about 1/2" thick and serve hot or cold.

I had to giggle when I typed this recipe up. Numerous times it said to use a fork...and I lost count of the number of times my dad scolded me for using a fork while cooking ....gee, if Betty Crocker used a fork while cooking, it must be alright!! Lol