Ask HN: What branch of CS does this recipe problem belong to?

I find that I waste a lot of food. As a side project, I'm trying to come up with some meal plans that will combine preexisting recipes such that there is minimal waste left over. E.g. I use some of ingredient X in recipe 1, and then some in recipe 2, etc. There are constraints set by the size of the units my supermarket sells the ingredients in.

Unfortunately, I have no idea where to start with this problem (I can code but don't have a CS background). I'm trying to start by finding out what domain it belongs to. Is it linear programming? Would machine learning be useful here?