I just analyzed 1.9M recipes and can now report that the yummy simplicial complex is arguably *not* flag. The following flavor trios have far fewer recipes containing all three ingredients than the recipes with pairs of ingredients would predict.
An open problem in culinary mathematics: Consider the π¦π’πππ¦ π πππππππππ πππππππ₯ Y on vertex set I = {ingredients} where ΟβY iff the ingredients in Ο appear in a single good recipe. Question: Is Y a flag simplicial complex? (A complex Y is ππππ when ΟβY iff {x,y}βY for all x,yβΟ.)