In a large (10-inch) skillet set over medium heat, cook the bacon and onions, stirring occasionally, until the bacon is crispy and the onions are golden, about 10 minutes.
Scoop the potatoes into a microwave-safe bowl and splash with a few tablespoons of water. Cover with plastic wrap, poke a few holes in the top and microwave at 100% for 3 minutes, until mostly cooked. Tip out the water and add the potatoes to the pan, raise the heat to medium-high until the potatoes begin to crisp, about 4 minutes. Sprinkle the skillet with cheese and hot sauce.
Scoop the mixture into warm tortillas and top with chicharrón and more hot sauce.