To make Luby's lime gelatin, prepare the ingredients, which include 2 packages or 5 ounces of lemon gelatin, 2 packages or 5 ounces of lime gelatin, 2 1/2 cups of boiling water, 1 1/4 cup of mayonnaise, and 1 1/2 cup of whole milk. Set those aside and gather one pound of large-curd cottage cheese, half a cup of slightly chopped medium pecan pieces, and 2 1/2 cups of crushed and drained pineapple.
Put the dry gelatin mixtures in a bowl and add 2 1/2 cups of boiling water. Stir the mixture until all of the dry particles have dissolved and the mix is clear. In a separate mixing bowl, whisk together the milk and mayonnaise until the mixture is smooth. When it is ready, pour it into the gelatin mixture.
Fill another large bowl halfway with ice and then put the bowl containing the gelatin mixture on top. Push this bowl down so that the sides are submerged in the ice. Stir the mixture occasionally, and when the gelatin has half-set, add in the cottage cheese, crushed pineapple and pecans. Pour this mixture into individual molds or a Bundt cake pan, and let it refrigerate overnight until slightly firm.