1 tablespoon olive oil
1 onion, diced
4 cups cooked chicken, shredded
1 teaspoon ground cumin
1 teaspoon chili powder
2 ( 15-ounce) cans green enchilada sauce
3 cups grated cheddar cheese
Diced tomatoes, chopped cilantro, and sour cream, for serving
In a medium skillet, heat the olive oil over medium-high. Add the onion and cook, stirring occasionally, until tender and caramelized, about 10 minutes.
In a large bowl, toss the chicken with the cumin and chili powder.
In a slow cooker, pour in about ¼ can of enchilada sauce, spreading evenly across the bottom. Place a tortilla in the slow cooker on top of the sauce. Pour a bit of the sauce on top. Sprinkle on some of the chicken mixture, then some caramelized onions, followed by some cheese. Top with another tortilla. Repeat this process, gently pressing down the layers to compress them and help them stay together (don’t worry, the layers will shrink down as they cook). Top the final tortilla with any remaining enchilada sauce and cheddar.
Cover and cook on low for 5 to 6 hours, until the cheese has melted and the enchilada is warmed through. Serve with diced tomatoes, chopped cilantro, and sour cream.