Begin by placing the uncooked chicken breasts in a large pot. Pour the chicken broth over the chicken and stir in one teaspoon of garlic powder. Bring the pot to a boil over medium-high heat, allowing the chicken to cook through until it's fully done.

Once the chicken is cooked, remove it from the pot and set it aside to cool slightly. Shred the chicken into bite-sized pieces using two forks.

In the same pot, heat two tablespoons of vegetable oil over medium heat. Add the diced onion and a pinch of salt. Sauté the onion until it becomes translucent and tender.

Sprinkle in the two tablespoons of flour to the onions and cook for a minute, stirring continuously to create a roux.

Gradually add the chicken broth back to the pot, whisking it in as you go until the mixture thickens and forms a smooth sauce.

Stir in the can of diced tomatoes, the shredded chicken, and the remaining spices. Combine everything well until the chicken is nicely coated.

Preheat your oven to 350°F. Warm the corn tortillas slightly on a hot skillet until they're pliable.

Take one tortilla and fill it with a generous scoop of the chicken mixture, sprinkling cheese over the top. Roll up the tortilla tightly and place it seam-side down in a baking dish. Repeat this process until you’ve filled all the tortillas.

Pour any remaining sauce over the top of the enchiladas and sprinkle the remaining cheese over the top.

Bake the enchiladas in the preheated oven for about 20-25 minutes, or until the cheese is melted and bubbling. Allow them to cool slightly before serving.