Cut green peppers in half lengthwise. Remove seeds and membranes and discard. Cook the green pepper halves, uncovered, in boiling water for 5 minutes. Invert to drain. Sprinkle the insides of peppers lightly with salt.
In a large saucepan cook pork, onion, celery, and garlic until pork is brown and onion is tender. Drain off fat. Stir in oysters. Cook oyster mixture, uncovered, about 2 minutes more.
Stir bread crumbs, tomato, salt, and pepper into pork mixture. Stuff peppers with bread crumb mixture.
Place stuffed peppers in a 1-1/2-quart rectangular baking dish. Bake, uncovered, in a 350 degree F oven for 30 to 35 minutes or until hot. Makes 6 servings.