For the puffed tortilla: Season the masa flour with salt and knead softly until a smooth dough is achieved. Form small balls, 30 grams each, and flatten in a tortilla press using two sheets of plastic. Fry in hot vegetable oil (160°C) for 3 minutes, constantly spooning hot oil over the top to achieve the puff. When completely cooked (golden brown) remove from oil and drain. Carefully cut a 6cm opening on the top part of the puff to fill tortilla before serving.
For the mashed beans: cook in a clay pot on medium heat, the soaked beans with the onion, epazote herb, and garlic in the water for 3 hours, or until beans are cooked and soft. Season with salt, and mash with only the minimum amount of liquid needed to obtain a smooth paste and pass through a fine sieve to remove skins.
For the Salsa de Molcajete: Char the onion, garlic and serrano pepper on a comal or cast iron skillet. Set aside. Roast the tomatoes on medium low heat until they are completely cooked (20 minutes approx.). Mash all ingredients in the “molcajete”, including the cilantro and dried grasshoppers, season with salt, and set aside.
For the egg: Cook the eggs for 5 minutes in boiling water. When cooked, remove from hot water, peel and allow to rest in fresh water until needed.
To serve: Fill the puffed tortilla with the beans, the salsa and top with the egg.