Preheat oven to 350 degrees. Mix all of the ingredients for the crust together. The batter will be lumpy. Spread into a 9x9 casserole dish. In a large frying pan brown the ground beef and drain the fat out. Add the chopped onion and cook until clear. Add in the remaining bean mix ingredients and cook until hot. Spoon the bean mixture onto the batter. Cook in the oven for 30 minutes. In the last 15 minutes of cooking you can add shredded cheese to the top for added flavour. For a large 9x13 casserole just double the recipe.