Prepare the chicken mixture:
In a medium bowl, combine the shredded chicken, cream cheese, sharp cheddar cheese, diced jalapeños, and diced red bell pepper. Stir until the ingredients are well mixed and the cream cheese is fully incorporated. Set aside.

Prepare the creamy sauce:
In a small saucepan, melt the butter over medium heat. Add the flour and whisk to create a roux. Cook for about 1 minute until lightly golden.
Slowly add the heavy cream and chicken broth while whisking to avoid lumps.
Stir in the garlic powder, onion powder, cumin, chili powder, salt, and pepper. Bring the sauce to a simmer, cooking for 3-5 minutes until it thickens. Remove from heat and set aside.

Assemble the enchiladas:
Preheat your oven to 375°F (190°C).
In a large skillet, heat the olive oil over medium heat. Lightly warm the tortillas in the skillet for about 30 seconds on each side to make them more pliable.
Spread a small amount of the creamy sauce in the bottom of a 9×13-inch baking dish.
Take each tortilla and spoon a generous amount of the chicken mixture into the center. Roll the tortillas up tightly and place them seam side down in the baking dish.

Top with sauce and cheese:
Pour the remaining creamy sauce over the top of the enchiladas, covering them evenly. Sprinkle the shredded mozzarella cheese and chopped green onions on top.

Bake:
Bake the enchiladas in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly and the sauce is bubbling around the edges.

Serve:
Let the enchiladas cool for a few minutes before serving. Garnish with additional chopped green onions or cilantro if desired. Serve with a side of rice, beans, or a simple salad.