1 c. flour
3/4 c. cornstarch
2 tbsp. oil
3/4 c. water, or more if needed to make a thin batter
1 1/2 tsp. baking powder
1 1/2 tsp. salt
1 egg

Mix together, beating until smooth. This makes a delicious golden brown crust. Unused portion can be frozen for future use. Just defrost, whip it up, and it's like fresh batter.