Heat the olive oil in a large skillet over medium-high heat.
Add the finely chopped onion and cook, stirring occasionally, until translucent about 5 minutes.
Stir in the ground cumin, paprika, kosher salt, garlic powder, and dried oregano until fragrant, about 30 seconds.
Add the shredded rotisserie chicken and toss to coat evenly with the spices.
Pour in the water, then add the diced chipotle pepper and the chipotle in adobo sauce; stir to combine.
Reduce the heat to low and simmer, stirring occasionally, until the mixture thickens about 3 to 5 minutes.
Warm the tortillas, fill with the chipotle chicken, and top with your desired toppings; serve immediately.
