Stroganoff Sandwich

1 1/2 lbs ground beef

1 med onion, chopped

6-8 bacon strips, cooked and crumbled

2 garlic cloves, minced

2 tbsp flour

1/2 tsp salt

1/2 tsp paprika

1/8 tsp nutmeg

1 can (10 3/4 ozs) condensed cream of mushroom soup

1/2 cup sliced fresh mushrooms

8 hamburger buns

1 cup (8 oz) sour cream