Heat a large skillet over medium-high heat. Toast the tortillas for 30-60 seconds on each side, until edges are browned (no oil needed). prep

Stack the toasted tortillas on a plate and cover with foil or an upside-down bowl to keep them warm. prep

Lower the heat to medium, add the cooking oil, and swirl to coat the skillet. Add the chicken breast and cook for 5-7 minutes per side, until the chicken is fully cooked (165ºF internal temperature). Transfer to a cutting board to cool. prep

While the chicken cooks, prepare the green chile sauce. Add the diced green chiles (with liquid) to a blender and purée until smooth. mix

In a small sauce pot, heat the oil, flour, cumin, garlic powder, and onion powder over medium heat. Stir until the mixture starts to bubble. Once bubbling, continue cooking and stirring for 1 minute. mix

Carefully add the water and puréed green chiles to the sauce pot, whisking to combine. Allow the sauce to simmer, stirring often. Once simmering, remove from heat and season with salt. Set aside. mix

In a large bowl, combine the sour cream, half of the shredded pepper jack cheese, sliced green onions, garlic powder, cumin, cayenne, and salt. Finely dice the cooked chicken and add to the bowl. Stir until well mixed. mix

Add about ¼ cup of the prepared filling to each tortilla and roll it closed. Place the filled tortillas seam-side down in a casserole dish. assemble

Pour the prepared green chile sauce over the enchiladas and top with the remaining shredded pepper jack cheese. Bake for 30 minutes, or until the sauce is bubbling and cheese is melted. bake