Preheat the oven to 350°F (175°C).

In a skillet, heat olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes. Add the minced garlic, cumin, chili powder, salt, and pepper, and cook for an additional 1-2 minutes until fragrant.

In a large bowl, combine the shredded chicken, half of the cheddar cheese, and half of the Monterey Jack cheese with the sautéed onion mixture. Mix well.

In a separate bowl, whisk together the sour cream and chicken broth until smooth.

To assemble the enchiladas, warm the corn tortillas in a dry skillet or microwave until pliable. Spoon about 1/4 cup of the chicken mixture onto each tortilla, roll it up, and place it seam-side down in a greased 9x13 inch baking dish.

Once all the enchiladas are in the dish, pour the sour cream sauce evenly over the top. Sprinkle the remaining cheddar and Monterey Jack cheeses over the sauce.

Bake in the preheated oven for 25-30 minutes, or until the cheese is melted and bubbly.

Remove from the oven and let cool for a few minutes before serving. Garnish with fresh cilantro.