A
recipe that includes many free variables, that normally include a set of acceptable values.
For example, the metarecipe for risotto would specify that you fry the onions with some tasty thing, and then throw in the rice, fry it, and slowly cook the whole thing with a suitable stock.
It is up to the individual cook to substitute, for example, sausage for the "tasty thing" and chicken broth for the "suitable stock".
Eminent metarecipes exist also for couscous and generic pasta with sauce.