Heat the oil in a medium nonstick skillet over medium heat. Add the onion and cook, stirring often, until softened, about 5 minutes. Add the garlic, cumin, oregano, and salt and cook, stirring constantly until fragrant, 30 seconds.
Add the tomatoes, broth, chipotles, and chicken and cook, stirring occasionally, until chicken is heated through, about 3 minutes.
Place two tortillas on top of each other and spoon the chicken mixture evenly into the layered tortillas. Sprinkle evenly with cotija. Serve with lime wedges and desired toppings.
Place two tortillas on top of each other and spoon the chicken mixture evenly into the layered tortillas. Sprinkle evenly with cotija. Serve with lime wedges and desired toppings.
Heating tortilla instructions
Cook the tortillas until they are toasted in a large skillet set over high heat, approximately 30 seconds or so per side, then stack them on a large sheet of aluminum foil. Wrap the foil around the tortillas, and place the package into the oven to heat. 350°F.