Cooking was one of the best mechanics in the Legend of Zelda: Breath of the Wild, and it's back in Hyrule Warriors: Age of Calamity, but in a different way.
The fun little sizzle dance the ingredients do in the pot is gone, unfortunately. However, cooking food does still play an important role in the game. The effects, which include stat bonuses, are thankfully still there.
The option to cook in the game shows up during a mission select screen. It looks like this:
It can be easy to gloss over, but once you select the option, you'll get a list of available meals based on your current ingredients.
By the way, unlock High Spirits Produce on the main map screen as soon as possible, as it will let you buy more ingredients for meals, instead of scavenging them from missions. It's located in the Kakariko Village area on the map.
Simply select the available meal and reap the benefits.
Collect ingredients, experiment, and don't underestimate the power of a few well-placed stat bonuses. They might be the difference between better rewards, faster kills, and simply staying alive.