Salvadoran Stuffed Corn Tamales

Name: Salvadoran Stuffed Corn Tamales
Cuisine: American, Latin American
Ingredients: 2 cups corn masa harina (corn flour); 1 ½ cups warm water or chicken broth; ½ cup vegetable shortening or lard; 1 tsp baking powder; ½ tsp salt; 1 cup cooked red beans, mashed; ½ cup queso fresco or grated hard cheese; 1 small onion, finely diced; 1 clove garlic, minced; 1 tbsp vegetable oil; ½ tsp cumin; Salt and pepper to taste; 8-10 banana leaves (cut into 10-inch squares, softened by passing over an open flame)