Shrimp Stuffed Red Peppers
["4 large red bell peppers", "6 Tbsp. butter or margarine", "1/2 c. onions, finely chopped", "8 Tbsp. flour", "2 c. sour cream", "2 tsp. lemon juice", "2 tsp. Dijon mustard", "1 (4 oz.) can sliced mushrooms", "4 c. cooked and shelled small shrimp (1 1/2 lb.)", "2 cans sliced water chestnuts, drained", "1 1/2 c. Jack cheese, grated"]
["Cut peppers in half lengthwise; cut out stems, seeds and pulp. Drop into boiling salted water and cook, uncovered, for 4 minutes; remove and turn cut side down to drain."]
["red bell peppers", "butter", "onions", "flour", "sour cream", "lemon juice", "mustard", "mushrooms", "shrimp", "water chestnuts", "Jack cheese"]