Add the 6 rodajas de tocino pieces to a cold skillet, then set over medium heat. Cook, stirring occasionally, until the 6 rodajas de tocino is crispy, about 6–8 minutes. Use a slotted spoon to transfer the 6 rodajas de tocino to a paper towel-lined plate. Pour off all but about 1 tbsp of the rodajas de tocino drippings from the skillet.

Return the skillet to medium-high heat with the reserved drippings. Add the diced papas Yukon Gold medianas limpias y in a single layer. Season with ½ tsp ajo en polvo, ½ tsp pimentón, and ¼ tsp sal. Cook undisturbed for 4–5 minutes until a golden crust forms on the bottom, then stir and continue cooking for another 4–5 minutes until the 2 papas Yukon Gold medianas limpias y are golden and fork-tender. Transfer to the plate with the 6 rodajas de tocino.

In a mixing bowl, whisk together the 6 huevos grandes, 2 tbsp leche entera, ¼ tsp sal, and ¼ tsp pimienta negra until fully combined and slightly frothy, about 30 seconds.

Reduce the heat to medium-low. Wipe out the skillet and add the 1 tbsp mantequilla sin sal. Once the 1 tbsp mantequilla sin sal is melted and foamy, pour in the 6 huevos grandes mixture. Let the 6 huevos grandes sit undisturbed for about 20–30 seconds until the edges just begin to set, then use a spatula to gently fold and push the 6 huevos grandes from the edges toward the center. Continue folding slowly — do not stir constantly — until the 6 huevos grandes are just set and still slightly glossy. Remove from heat immediately; they will finish cooking from residual heat. Season with a pinch more ¼ tsp sal if needed.

Warm the 8 tortillas de harina pequeñas de 6 pulgadas one at a time directly over a gas burner on medium-low heat for about 20–30 seconds per side until lightly charred and pliable. Alternatively, wrap the stack of tortillas de harina pequeñas de 6 pulgadas in a damp paper towel and microwave for 45–60 seconds.

To assemble each taco, lay a warm 8 tortillas de harina pequeñas de 6 pulgadas flat and add a spoonful of scrambled 6 huevos grandes, a few pieces of rodajas de tocino, and a scoop of crispy 2 papas Yukon Gold medianas limpias y. Top with shredded 1 cup queso cheddar rallado o Monterey Jack, a spoonful of salsa, and any optional toppings — 1 aguacate mediano en rodajas o, 2 tbsp crema agria, 1 jalapeño mediano, and fresh cilantro fresco picado aproximadamente. Serve immediately with 2 limas enteras en gajos wedges on the side.