If you want to use the vernacular, your bf uses a more common phrasing.

“How is the food going?” sounds unnatural, because generally we use the phrase “x is going well” to describe an action, a process, or something “on-going” and continuous (A job, school, something that takes awhile). “Food” is not an action or a process, it’s an end result or a goal. We refer to goals as “coming along” because there is an end result (a meal) that will be completed in the near future.

For example, if you were building a house, it would be most natural to say “How is the work going?” and “How is the house coming along?” The house is the end result so it’s coming along (into your final possession) and the work of building it is a process that is going (like imagine it on a timeline, going down the line).

Anyway, both are grammatically correct, but yes, your friend’s versions sounds natural for colloquial reasons.

… seriously, I think both ways are fine!