Gluten Free Onion Ring Batter More simple version: Forget the brown rice flour. Use G.F flour and tapioca flour only. 1/4 of a cup for each. Use 1/2 cup of milk to substitute the beer. Don't forget the garlic powder and the dill, it really makes a difference. You can use this exact same batter to to fry other vegetables and also fish. For fish, season it with salt and pepper before a coat of dry flour. Then dip in batter, then fry.