Begin by preparing the masa dough. In a large bowl, combine masa harina, baking powder, and salt. Gradually add warm water or broth while mixing with your hands until the dough reaches a soft, pliable consistency. Add vegetable shortening or lard, kneading thoroughly to incorporate air into the dough. This step ensures the tamales are light and fluffy.

Prepare the filling. Heat vegetable oil in a skillet over medium heat. Sauté diced onions and minced garlic until fragrant, about 3 minutes. Stir in mashed red beans, cumin, salt, and pepper. Cook for 5 minutes until the mixture thickens slightly. Remove from heat and let cool. Once cooled, fold in the crumbled queso fresco.

Lay out the softened banana leaves. Place a small ball of masa dough (roughly the size of a golf ball) in the centre of each leaf. Flatten the dough slightly into a disc, about 4 inches wide.

Spoon 1-2 tablespoons of the bean and cheese filling onto the centre of the masa disc. Carefully fold the edges of the masa over the filling, enclosing it completely. This ensures the filling remains inside during steaming.

Fold the banana leaf around the masa, forming a secure package. Fold the sides first, then the top and bottom, tucking them neatly. Tie each tamal with kitchen twine to keep it secure.

Arrange the wrapped tamales in a large steamer basket, leaving space between each one for steam circulation. Add water to the steamer, ensuring it does not touch the tamales. Cover and steam over medium heat for about 1 hour, checking periodically to ensure the water does not evaporate completely.

To test for doneness, unwrap one tamal. The masa should be firm and easily separate from the banana leaf. If it sticks, steam for an additional 10-15 minutes. Allow the tamales to rest for 5 minutes after steaming to firm up further.

Serve the tamales warm, leaving them partially wrapped for an authentic presentation. Pair with curtido (pickled cabbage salad) or a spicy tomato salsa for added flavour. Garnish with fresh cilantro or a squeeze of lime for a vibrant touch.