I’ve got Mining/Engi for professions with max cooking & fishing.
There isn’t any professions that really compliment cooking other than fishing.
You can level cooking from 1-100 purely from fishing and depending on which feast recipe you get another profession isn’t necessary JUST for fishing.
For Gral’s Devotion the only non fishing related items are Roast Duck delight & Mighty Mammoth Ribs which is easily learnt/acquired without any other professions.