Heat oven to 325 degrees. Butter a 1 1/2-quart casserole. In a small skillet, saute the bacon and onions until the bacon is crisp and onions are lightly browned; drain well. In a large bowl, combine the remaining ingredients.
Add bacon-onion mixture; mix well. Pour bean mixture into prepared casserole. Bake uncovered at 325 degrees for 1 1/2 hours. Enjoy!