Preheat the oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish.
In a large skillet, heat the vegetable oil over medium heat. Add the chopped onion and cook until softened, about 5 minutes.
Add the minced garlic and chopped jalapeño to the skillet and cook for 1 minute until fragrant.
Stir in the ground cumin, chili powder, smoked paprika, and cayenne pepper. Cook for 30 seconds to toast the spices.
Add the shredded chicken, drained diced tomatoes, and chopped cilantro to the skillet. Stir well to combine and cook for 3-4 minutes until heated through. Season with salt and black pepper to taste. Remove from heat.
Warm the corn tortillas in a dry skillet or microwave until pliable to prevent cracking when rolling.
Spread 1/2 cup of enchilada sauce evenly on the bottom of the prepared baking dish.
Place about 1/3 cup of the chicken mixture in the center of each tortilla. Sprinkle with a tablespoon of the shredded Monterey Jack and cheddar cheese blend.
Roll up each tortilla tightly and place seam side down in the baking dish.
Pour the remaining enchilada sauce evenly over the rolled tortillas.
Sprinkle the remaining shredded cheese evenly over the top of the enchiladas.
Cover the baking dish with aluminum foil and bake for 20 minutes.
Remove the foil and bake for an additional 10 minutes or until the cheese is bubbly and golden.
Remove from the oven and let the enchiladas rest for 5 minutes before serving.