01 - 
                Heat 1 tablespoon of oil in a medium skillet over medium heat. Sauté the onion, garlic, and jalapeño until golden. Add the black beans, bring to a simmer, and season with salt to taste. Transfer contents to a blender and puree until smooth. Set aside.
              
              
              
                02 - 
                In a large bowl, combine masa harina and salt. Gradually mix in warm water until a dough forms. Knead the dough thoroughly for about 3 minutes to ensure water is absorbed.
              
              
              
                03 - 
                Portion the dough into about 15 equal pieces and roll each into a ball. Cover with a damp cloth or plastic wrap to retain moisture.
              
              
              
                04 - 
                Using a tortilla press lined with parchment paper, place a dough ball on the press, fold over the paper, and gently flatten the dough.
              
              
              
                05 - 
                Place 1 ½ tablespoons of black bean puree and 1 ½ tablespoons of shredded Oaxaca cheese in the center of the flattened masa. Fold the bottom edge upwards, then fold the top corners to form a triangle. Press gently to seal.
              
              
              
                06 - 
                Preheat a griddle or skillet over medium-high heat. Place the tetela onto the skillet and cook for approximately 3 minutes on each side. Transfer to a plate and cover with a kitchen towel to keep soft. Repeat for remaining tetelas.
              
              
              
                07 - 
                Serve hot with your choice of salsa, Mexican crema, crumbled queso fresco, and fresh cilantro.