Heat the olive oil in a large skillet over high heat. When the oil shimmers, add the chicken and onion. Cook, stirring occasionally, until the chicken is browning, about 5 minutes. Add the chipotle peppers, enchilada sauce, oregano, salt, and 1/3 cup water. Reduce the heat to medium and simmer until the sauce has thickened slightly, about 10 minutes. Remove from the heat and shred the chicken. Meanwhile, make the salsa. Combine all ingredients in a bowl and season with salt. Heat a large skillet or griddle over medium heat. Add 2-3 tortillas and a handful of cheese, cover the pan and let cook 30 seconds, until the cheese is melty. Flip and cook another minute, until you see the cheese crisping, then flip and add another tortilla on top. Remove from the heat. Stuff the tortilla with avocado, salsa, and chicken. Top with crema and additional salsa. Enjoy!