food

These works have substantial focus on food, its preparation or consumption.

That's pretty vague.

Concretely, it's common in manga to devote several panels or pages to very detailed images and discussion of food, out of proportion with its importance to the plot. In isekai stories, the protagonist may long for a taste of home, and spend time trying to recreate Japanese dishes, and the locals are likely to be wowed by the exotic food. In a number of stories, the food is the main focus, with the fantasy world serving just as a backdrop.

Also in non-isekai stories, there are often chapters devoted to food: making chocolates for Valentine's day, or curry on a class trip, or okayu (rice porridge) for a sick classmate.

If the food itself receives a lot of attention, then the work belongs in this tag.