1) Preheat the oven to 400°F.
2) Coat the bottom of a baking dish with butter.
3) Place the fish on the baking dish and dredge it with the barbeque spice and celery salt.
4) In a bowl, mix together buttermilk, vinegar and tomato juice.
5) Gently stream the buttermilk mixture over the fish.
6) Bake for 10 minutes or until the fish is tender.
7) Carefully place the fish on the serving plate with a lemon wedge on side.