Scoop avocados into a medium bowl and mash to desired consistency. Stir in red onion, lime juice, chili powder, cumin and salt. Cover and store in fridge until ready to serve.
Cut pork loin into ½-inch thick slices. Heat oil in a large skillet or nonstick pan to medium-high heat. Add pork to pan in an even layer (with the included bacon topping). Cook 4-6 minutes, until lightly browned, rotate and cook other side until center reaches an internal temperature of at least 145° F. Remove from heat and cool slightly, then cut pork slices into ¼-inch strips.
Heat a clean pan to medium heat, lightly butter if desired. Place tortilla(s) in pan, sprinkle half with desired amount of cheese, top with cooked pork and sliced tomato. Fold over and heat until bottom is lightly browned, rotate and heat until other side is lightly browned and cheese is melted. Note: Amount of tortillas you cook at a time depends on pan and tortilla size.
Add prepared homemade guacamole and cilantro to each before serving.