Sweet and Sour Meatloaf

1 15 ounce can tomato sauce
1/2 cup brown sugar
1/4 cup vinegar
1 teaspoon prepared mustard
2 pounds lean ground beef
1 pound ground pork
2 eggs, slightly beaten
2 small onions, minced
1/2 cup fine soft bread crumbs
1/4 teaspoon pepper

Mix the first four ingredients in a small bowl. This is the sauce.

Mix the other ingredients and a cup of the sauce in a large bowl.

Place the mixture in a 2 quart loaf dish. Press into a loaf, with a raised center so that there is space for the fat to collect.

Pour 1/4 to 1/2 cup sauce over the loaf.

Bake at 375F for 1 hour 15 minutes, basting with 1/4 cup sauce after 30 minutes.