Place potatoes in a pan with cold salted water, bring to a boil and immediately turn heat down to a simmer. Cook potatoes until fork tender, about 15 min. Drain potatoes and set aside.
Meanwhile, in a large bowl combine the masa flour, salt, and baking powder. Pour in 1 ¾ cups of warm water. Mix with your hand. The dough should be the consistency of soft playdough. If it is too dry add more water, until you reach the desired consistency. Cover with a moist paper towel and let rest 5 min.
Set a large sauté pan to medium heat and add 1 cup of salsa verde. Bring to a simmer and add half of the potatoes. Stir to coat potatoes with sauce. Season and remove from heat. Repeat these steps with a different pan, the rest of the potatoes, and the salsa roja.
Uncover your dough and divide it into 2oz. balls. You will be able to make about 12ea. Place on a surface covered with plastic wrap. Flatten the balls with your hands to make a round patty about 1/3 in. thick. Continue this process with the rest of the balls.
Set a large cast-iron pan, comal or griddle to medium-high heat. Add 1 tbsp. of oil (optional). Once the oil is hot add the masa rounds and let cook for 3 min. and then flip. Let cook for 3 -4 min more until brown spots appear on the gordita and it is hard to the touch.
Repeat with the rest of the rounds. Then, using a sharp serrated knife cut a slit in the edge about half-way around its circumference, making a sort of pocket. Fill each gordita with the desired potato mixture. Serve with sliced avocado or guacamole.
These gorditas can also be fried in a shallow pan with oil at 350F. Fry 2-3 minutes on each side until golden brown, then cut, and fill.