Low carb meatloaf

Chop

7 medium onions
3/4 lb mushrooms

Reserve 2 chopped onions and half the mushrooms for the sauce. Combine the remaining onions and mushrooms with

5 lbs ground beef
6 large bell peppers, chopped
3 green onions, chopped
3 stalks celery, chopped
3/4 lbs bacon, partially cooked, chopped
6 cloves garlic, minced
3 eggs, plus
5 egg whites
1 cup water
5.5 ounces tomato paste (1 small can)
5 tbsp Worcestershire sauce
2 tbsp dried oregano

2 tbsp chili powder 
1 1/2 tbsp garlic powder
1 1/2 tbsp onion powder