Spaghetti Sauce

1 pound ground beef
4 tablespoons vegetable oil, divided
1 small onion, finely chopped
1 (15 1/2 ounce) can tomato sauce
1 1/2 cups water
1/2 teaspoon pepper
1/2 teaspoon red pepper (optional)
1 (29 ounce) can tomato pur?e
1 (6 ounce) can tomato paste
1 teaspoon salt
1/2 teaspoon oregano
1/4 to 1/2 cup granulated sugar (optional)
2 pounds Italian sausage links, sliced

Brown ground beef in 2 tablespoons hot oil in frying pan. When almost browned, add onion and continue browning until onion is tender. Pour meat and onion into a 3 1/2-quart crockpot. Add remaining ingredients except sausage. If you like sweeter sauce, add 1/4 to 1/2 cup sugar to the crockpot. Set crockpot to LOW setting.

Brown sausage in remaining 2 tablespoons oil. When brown, place sausages in sauce in crockpot. Continue cooking for 12 hours.