1 pkg. lemon Jello (can use diet)
1 c. hot water
1/2 c. cold water
1 1/2 tbsp. vinegar
1/2 c. mayonnaise (can use no fat)
1/2 tsp. salt
1 tsp. grated onion
2 c. finely shredded cabbage

Combine gelatin, water, vinegar, mayonnaise and salt. When set, beat until fluffy and stir in onion and cabbage. Pour into ring mold and chill to set. Unmold on lettuce and decorate with tomatoes.