Now I didn't mind so much plain old Jello. But when the adult women of the family started putting in bits of carrots, celery, lettuce and who knows what else, well that always made me want to gag.
That is usually aspic. Aspic was popular during times of rationing. It was a way to stretch the food. Many of the recipes you saw as a kid were foods popular during rationing, things like cottage cheese and casseroles. I found a book about it at the library.