Arrange chicken in a 9" x 9" glass baking pan. Top with eggs. Mix together soup, onion, 1/4 cup mayonnaise and lemon juice. Spoon soup mixture over ingredients. Top with broccoli and cheese. Microwave bread crumbs with margarine on full power for 30-40 seconds to toast. Sprinkle bread crumbs over all. Microwave on full power for 7-10 minutes, rotating once, until cheese is melted and soup bubbles.