Mining.
None of the food techs carry any guarantee of a matching resource. Mysticism is no guarantee of founding a religion, and besides I prefer a rival to do the work of building a shrine for me. Often a strategic resource is on a riverside, obviating the Wheel as a necessity for early security.
Copper or no copper, forests or no forests, I will want to adopt Slavery early on. Preferably as my first Settler embarks on their migration. So, I like to open with a food tech and then Bronze Working.
Hunting's pretty cool as my second, as it opens Animal Husbandry, gives me a Scout, and enables the last resort of Barbarian deterrent.