In a large covered pot, simmer consomme, 1/2 can water, lemon, vinegar, cayenne, Worcestershire, celery, onion, green pepper, salt, Tabasco sauce and garlic for 1 1/2 hours. Melt the gelatin in 1/2 cup water in a saucepan. Shred pot roast and add to gelatin. Strain the stock through a colander, add the meat-gelatin mixture and pour into an 8x8 inch pan. Chill Before gelatin has completely set, mix meat through so it is evenly distributed. Chill thoroughly. Cut into squares and serve on a lettuce leaf with a dollop of mayonnaise.
Note: This may also be served for luncheon or as a hot weather dinner with fresh fruit and rolls or French bread.