Fill a large pot or dutch oven with water and bring to a boil over high heat. Add the potatoes and boil for 20 to 25 minutes, or until they are fork tender. Drain the potatoes and transfer them to a large bowl.
Melt the butter in the pot used for cooking the potatoes over medium-high heat. Add the garlic and saute for 30 seconds, or until it is fragrant.
Add the potatoes, cumin, chili powder, and salt and mash the potatoes until they are creamy and smooth. Set aside.
In a large nonstick skillet, heat oil over medium-high heat.
Spread about 1/4 cup of the mashed potatoes on one side of the tortillas and fold them to create tacos.
Fry each taco for about 2 minutes per side, or until the tortillas are golden and crispy, flipping the taco carefully with a small spatula.
Place the tacos on a plate or baking sheet covered with paper towels to soak up any excess oil. Continue frying the tacos in batches until complete.
Stuff the fried tacos with a small handful of the cabbage, some pico de gallo, a generous amount of cotija cheese and some cilantro. Serve the tacos with the lime wedges.
For the pico de gallo
In a medium bowl, combine the tomatoes, red onion, lime juice, and cilantro and stir to combine. Season with salt.