In a large bowl combine first three ingredients and stir until smooth. The dough should be slightly sticky and form a ball when pressed together. To test, flatten a small piece of dough between your palms. If the edges crack, add water to the dough, a tablespoon at a time, until a test piece does not crack.
Divide the masa into 12 pieces and form each into a ball. Press or roll each into a 4-inch circle. Heat a dry cast-iron skillet or griddle over medium-high heat and cook the tortillas. When cool enough to handle, pick up each puffed tortilla and make a 1 1/2-inch slit about 1/4-inch from the edge to make a pocket, being careful not to cut all the way through the tortilla. Puree the Refried Black Beans and stuff 2 teaspoons of the bean puree in each pocket. Flatten to seal and spread the beans evenly. Reserve the stuffed tortillas on a tray covered with a barely damp cloth.
Heat 3 tablespoons of the oil in a large skillet over high heat. Fry the stuffed tortillas in batches, adding more oil as necessary, until they are a little crisp around the edges but still pliable. Drain on paper towels. Then place on a tray and keep warm in a 200 degree oven.
Heat the chicken in a small pan over low heat. Remove the tray of panuchos from the oven. Top each with a scant tablespoon of Roasted Tomato Salsa. Sprinkle on the chicken and Pickled Red Onions and top each with a small avocado slice. Serve warm or at room temperature.
*Variation: In case your tortillas do not puff, here is an alternative plan; fry them as is in the oil, and then spread with a very fine layer of beans followed by the other ingredients. They will still taste delicious.