preheat oven 375. Grease 8x12 baking dish.
In a skillet, heat 2 Tbl butter and cook onion to soften but not brown. About 3-5 minutes.
Add beef and cook breaking up meat with back of a spoon. Brown about 5 minutes. Stir in tomatoes, broth and season with salt and pepper. Reduce heat, and cook, stirring occasionally until most of liquid is cooked off (20 mins)
Pour into baking dish.
In a bowl, combine flour, powder, and 1/2 tsp salt. cut in the remaining 4 tbls of butter and cheese.
On a floured surface, roll or pat out dough into a 1/2 inch thick cound. Cut into 8 biscuits. Place biscuits close together on top of beef mixture. Bake until lightly browned 35 minutes.