If you wish to add fresh pineapple, kiwi, figs, or papaya, cook them first in sugar syrup until tender. When choosing additions, bear in mind how the flavors will complement one another.

Prepare any recipe for gelatin, below. Chill the mixture in a bowl, stirring frequently, until it is the thickness of unbeaten egg whites and falls from a spoon in sheets. If you inadvertently let the gelatin set, simply melt it over gently simmering water and start again. Stir into the gelatin or arrange artfully in the mold up to 1 ½ cups total:

Pour the mixture into a wet 3- to 4-cup mold. Refrigerate until set, about 4 hours, before serving.