Cut peppers in half lengthwise; discard seeds and membranes. Cook in boiling salted water for 5 minutes; drain. Arrange cut side up in 12x8x2-inch baking dish; sprinkle with salt.
Cook tofu, vegetables and garlic in butter in large skillet until vegetables are tender crisp. Toss with rice, 1 cup cheese, 1 teaspoon salt and pepper.
Fill each pepper half with 2/3 cup mixture. Bake, covered, at 350 degrees F. 25 minutes. Sprinkle remaining 1/2 cup cheese over cups. Bake 5 minutes, or until cheese is melted.