COOK cauliflower, covered, in a small amount of boiling salted water about 2 minutes; DRAIN; let COOL.
DISSOLVE gelatin in boiling water; STIR in vinegar and salt; CHILL until consistency of unbeaten egg white.
STIR in cauliflower, red and green peppers, and celery.
POUR into lightly oiled individual molds; CHILL until set.
UNMOLD each salad on a lettuce leaf; GARNISH with mayonnaise.
Per Serving (excluding unknown items): 285 Calories; 4g Fat (12.0% calories from fat); 6g Protein; 60g Carbohydrate; 1g Dietary Fiber; 2mg Cholesterol; 473mg Sodium. Exchanges: 1/2 Vegetable; 1/2 Fat; 4 Other Carbohydrates.