Preheat oven to 375°F (190°C) and grease a baking dish.
In a mixing bowl, combine shredded chicken, cream cheese, cheddar cheese, diced jalapeños, garlic powder, onion powder, cumin, and salt.
Fill each tortilla with the chicken mixture, roll tightly, and place seam-side down in the baking dish.
In a saucepan over medium heat, whisk together chicken broth and flour until smooth.
Stir in sour cream (or Greek yogurt) and chili powder, cooking until slightly thickened.
Pour the sauce over the enchiladas and sprinkle with Monterey Jack cheese.
Bake for 20-25 minutes or until cheese is melted and bubbly.
Let cool slightly before serving.
