This is called a utility function. This utility function U is defined by U(chicken) = 1, U(pork) = 2, U(steak) = 3. We prefer things with higher utility — in other words, we want to maximize the utility function!
It seems like you’ve got this backwards, given the stated preference ordering, yes? U(chicken) = 3, U(pork) = 2, U(steak) = 1 would make more sense.
It seems like you’ve got this backwards, given the stated preference ordering, yes? U(chicken) = 3, U(pork) = 2, U(steak) = 1 would make more sense.