Slice half the peppers in rings; set aside. Chop remaining. In bowl combine chopped peppers, pork, 2 teaspoons of the Worcestershire, and 2 teaspoons cracked black pepper. Shape in four 3/4-inch-thick patties. In large hot skillet cook patties over medium-high 10 to 12 minutes; turn once (160 degrees F internal temp.). Transfer to plates; cover. In same skillet cook pepper rings and mushrooms 3 minutes; sprinkle salt.

Wrap bread in paper towels. Microcook on HIGH for 30 seconds. For sauce, combine mayonnaise, remaining Worcestershire sauce, and black pepper. Place burgers on bread; top with pepper-mushroom mixture. Pass sauce. Makes 4 servings.