A lavish meal is created at an electric stove or fueled stove and requires 0.5 nutrition from any combination of animal products and meat, and 0.5 nutrition from vegetables to create. A colonist with cooking skill of at least 8 is required to create this meal. When eaten it causes the Ate lavish meal thought with a 12 mood bonus. A lavish meal provides 1.0 nutrition.
It's rather wasteful when compared to other meals; with the same ingredients you can make two fine meals for a total of 1.8 nutrition. Thus you should save this for mid-late game where food won't be an issue most of the time.