This is kind of obvious (from his point of view, there isn't much difference in methods, just in intended goals), but I think it's also congruent with how much those activities involve, functionally, forensic countermeasures.
I mean: a surgeon that leaves on her or his patient any "clue" except the planned effects of the operation (any sort of contamination, any uncontrolled side effects, any errors in timing or process) is a bad one. Food preparation is even more so: we want the food, but we don't want to know where it comes from, how its source was killed, how it was processed, what happened to what was left of it, nor, most of the time, who did it. We don't even want to know what's made of, or are more than willing to take other people/organizations' word for it, which is the source of about half of the jokes in the show.
I'm just grasping at symbolic straws here (bear with me, I'm distracting myself from some leftover anxiety), but, at least in my head, it's not a coincidence that Lecter's medical and culinary skills are not just useful during his murders, but also to cover them up. We all spend a lot of time, energy, and resources cleaning up after our killings — deploying forensic countermeasures against ourselves, in other words.