Sloppy Joe Stuffed Peppers

1 pound ground turkey
1 ounce onion, chopped, about 2 tablespoons
1 stalk celery, chopped
1 clove garlic, minced
1/2 cup tomato sauce
1 1/2 teaspoons white vinegar
1 1/2 Tablespoon Worcestershire sauce
1/2 teaspoon mustard
1/2 teaspoon salt
1/8 teaspoon pepper
8 ounces cheddar cheese, shredded
3 green peppers, halved lengthwise

Brown the ground beef, onion, celery and garlic; drain the fat. Stir in all of the remaining ingredients except the cheese and green peppers. Simmer 10 minutes. Meanwhile, parboil the peppers in a little boiling water 3 minutes; drain. Place the peppers in a baking dish. Stir half of the cheese into the hamburger mixture; fill the peppers with the meat. Top with the remaining cheese. Bake at 350º 15-20 minutes until hot and bubbly and the peppers are tender.