4 medium onions, peeled and cut into 1/2 inch rings.
flour for dusting
1/4 C buttermilk
2 tsp baking soda
1 cup cold water
1 cup flour
salt and pepper to taste
Toss the onions in some flour to start and let sit.
Mix batter in a separate bowl with a whisk. Dust off rings from the flour, dunk in batter and fry