It makes a ton of sense to have cooking/fishing pay off in some mechanical way, but simply replacing or overshadowing the present balance of consumables with a low-risk grindable system is less than ideal.
The solution could be that player-made food can be used to offer buffs to animal companions, familiars, summons, and henchmen. These could be basic stat increases, regen, temporary immunities, or other properties based on how complicated the food was to make. Continuous bonuses should only be equivalent to Magic Fang or Endure Elements. Immunities (like poison, fire, etc.) should last for less than a turn at most, and require advanced cooking with multiple steps.
This could carve out a niche that adds to the player economy without replacing it. Cheaper than potions, but only useful if you also manage NPC allies, which fits the communal theme of cooking.