Step 1: Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish. Pour about 1/4 cup of the enchilada sauce into the bottom of the prepared dish, spreading it evenly.
Step 2: In a large bowl, combine the shredded chicken, 1/4 cup of the enchilada sauce, chicken broth, sour cream, diced onion, minced garlic, chili powder, cumin, salt, and pepper. Mix until well combined. Stir in 1 cup of the shredded cheese into the chicken mixture.
Step 3: Warm the corn tortillas to make them pliable and prevent tearing. You can do this by wrapping them in a damp paper towel and microwaving for 30-60 seconds, or by quickly dipping each tortilla in warm oil for a few seconds (drain well).
Step 4: Lay a warm tortilla flat. Spoon about 1/4 to 1/3 cup of the chicken mixture down the center of the tortilla. Roll the tortilla tightly and place it seam-side down in the prepared baking dish. Repeat with the remaining tortillas and chicken mixture.
Step 5: Pour the remaining enchilada sauce evenly over the rolled enchiladas. Sprinkle the remaining 1 cup of shredded cheese over the top of the sauce.
Step 6: Bake for 20-25 minutes, or until the cheese is melted and bubbly and the enchiladas are heated through. If you like a slightly browned top, you can broil for the last 1-2 minutes, watching carefully to prevent burning.
Step 7: Remove from the oven and let rest for 5-10 minutes before serving. This allows the enchiladas to set and makes them easier to serve. Garnish with fresh cilantro, diced avocado, or a dollop of sour cream if desired.