Preheat the oven to 350°F
Make a seasoning mix: Add the chili powder, garlic powder, onion powder, cumin and black pepper to a small bowl, stir to combine.
Heat the canola oil in a large, non-stick skillet over medium heat. Add the chicken to the skillet and cook about 3 minutes per side, just to get the chicken going and to brown on the outside just a little bit.
Remove the chicken from the skillet and set on a plate or pan. Don’t worry that the chicken is not cooked all the way through; it will finish cooking in the sauce.
Do not wash the skillet, set it back over medium-low heat and add the butter.
When the butter melts, add the flour, cook stirring almost constantly for 1 minute.
Add the tomato sauce, prepared seasoning mix, and chicken broth, stir well to combine.
Raise the heat to medium-high, when the sauce comes to a simmer return the chicken to the skillet.
Lower the heat to medium-low, cover and cook 15-20 minutes until the chicken is cooked through. Keep the sauce at a simmer, Turn the chicken about half way through the cooking time, and stir the sauce occasionally.
Make sure the internal temperature of the chicken is at least 165°F at its thickest part.
Remove the chicken from the skillet and continue cooking the sauce, uncovered on medium-low to low heat for 10 minutes, stirring occasionally.
Stir in the half and half and cook on low heat, just enough to warm through, don’t allow the sauce to come to a simmer. Taste the sauce and add salt if needed.
Place the chicken on a cutting board or pan and shred using two forks.
Place the shredded chicken in a large bowl, add 1 cup of sauce, the corn and black beans. Stir well to combine.
Build the shredded chicken enchiladas: Add about ¼ cup of the sauce to the bottom a large casserole dish (10x13).
Working with one tortilla at a time, add 2 heaping tablespoon of the chicken mixture to the center, arrange so the meat is not mounded in the middle.
Fold one end in, then roll the flour tortilla. Place the tortilla seam side down in the casserole dish. Repeat with the remaining tortillas/chicken mixture.
Arrange the chicken enchiladas in the casserole dish so they fit snuggly without stacking.
Pour the remaining enchilada sauce over the tortillas and top with the shredded Monterey jack cheese.
Bake the enchiladas for 25-30 minutes to warm through and melt the cheese.
Garnish with chopped cilantro if desired