Preheat an oven to 400 degrees F (200 degrees C). Grease a 9x9 inch baking pan.
Whisk together the eggs, water, and vegetable oil in a bowl until evenly blended; set aside. Stir together the cornmeal, millet flour, rice flour, sugar, baking powder and salt in a separate large bowl, and make a well in the center. Pour the liquid mixture into the well and stir just until combined.
Pour the batter into the prepared baking pan and bake in the preheated oven until golden and the top springs back when lightly pressed, about 20 minutes.
