In the frying pan, brown the ground beef over medium-high heat, mincing as you go. Drain on a paper towel, then add to the slow cooker.
Wipe out the frying pan with a paper towel and add the bacon. Cook over medium-high heat until the bacon fat is rendered. Remove the bacon, drain on a paper towel, then add to the slow cooker.
Drain the bacon fat, reserving 2 tablespoons in the skillet. Saute the diced onions until soft. Drain the onions and add to the slow cooker.
Put the remaining ingredients in the slow cooker and cook on low for 5 to 6 hours or on high for 2 to 3 hours.
Oven Method
Put the ingredients into a 4-quart glass baking pan and bake in a 350° F/175° C oven for about 45 minutes.