Guacamole

1 envelope unflavored gelatin 1/4 c. cold water 1/3 c. boiling water 1 T. lemon juice 1 1/3 c. finely mashed avocado 1/3 c. mayonnaise 3/4 tsp. salt 2 T. finely diced onion 1. small ripe tomato (optional) Tortilla chips Tasting by Garrett Shutup