To the canister of a high-speed blender, add the first 7 ingredients, through oregano, and blend on high speed until smooth, about 1 minute. Notes – I used 3 chipotles and a generous tablespoon of adobo sauce and neither I nor my daughter found this to be spicy but use 1 if you’re very sensitive to spices, 2 if you’re probably average, and 3+ if you don’t find anything to be spicy which is the camp we’re in.
To a large skillet, add the olive oil, sauce from the blender, and simmer it over medium-high heat for about 5 to 7 minutes, or until the sauce is lightly bubbling and has slightly reduced and thickened.***
Add the chicken, stir to coat, and cook for about 3 minutes, or until completely coated and warmed through.
Place tortillas one by one over the flame of a gas stove for about 10 to 15 seconds per side, or as desired. For an electric stove, heat in a skillet until warmed though.
Add chicken to each tortilla and evenly garnish with red onions, cilantro, cotija, lime juice, and serve immediately. Extra chicken will keep airtight in the fridge for up to 5 days.
Notes
*I highly recommend a rotisserie chicken.**Panela or queso fresco may be substituted.***Tip: If you find the earthiness or smokiness of the chipotles or the acidity of the tomatoes to be a bit much, add 1 or 2 teaspoons of sugar to mellow it.