Bungeoppang (Fish-shaped bread with sweet red bean filling)

This recipe comes from: http://www.maangchi.com/recipe/bungeoppang 

Ingredientes: 

1 cup all purpose flour
½ teaspoon salt
½ teaspoon baking soda
1 tablespoon brown or white sugar
1 cup plus 2 tablespoons water
1 tablespoon vegetable oil
Sweet red beans (canned or homemade): or homemade. 

Instructions: 

1. Combine flour, salt, baking soda, and sugar in a bowl. Add water and mix it well.
2. Sieve the mixture through a strainer to get a silky batter without any lumps.
3. Heat up the bunggeoppang pan and turn the heat down to low.
4. Open the pan and grease both the upper and lower fish molds with a light coating of vegetable oil.
5. Pour the batter into one side of the fish mold until it’s ⅓ full. Add  1 tablespoon of sweet red beans to the center, and then gently fill up the rest of the fish mold to totally cover the red beans.
6. Close the mold and cook for about 3 minutes over low heat.
7. Turn the pan over and let it cook another 3 minutes. Open it and turn it over again for another 30 seconds, to make the bread a little more crispy.
8. Take out and serve immediately.