Preheat your oven to 400°F (200°C).

Measure out the skim milk, chicken broth, sour cream, and spices, preparing everything for assembly.

Melt 4 tablespoons of unsalted butter in a medium saucepan over medium heat. Whisk in 1/4 cup of all-purpose flour and cook for about 1 minute until light golden.

Gradually whisk in 1 cup of skim milk and 1 cup of chicken broth until smooth. Add the sour cream and cook over medium-low heat for 3-5 minutes until thickened.

Stir in 1 teaspoon of ground cumin, chopped green chilis, 1 tablespoon of chili powder, and season with salt and pepper to taste, simmering for another minute.

In a large mixing bowl, combine the shredded chicken, frozen corn, and chopped green onions. Pour the creamy sauce over and stir until well combined.

Warm the corn tortillas in a skillet over medium heat for about 30-40 seconds on each side until pliable.

Lay each warmed tortilla flat, scoop 2-3 tablespoons of filling onto the center, sprinkle with shredded mozzarella, and fold the tortilla in half.

Place filled tacos on a baking sheet and bake in the preheated oven for 12-15 minutes until the cheese is melted and tortillas are golden brown.

Let the tacos cool for about a minute before serving with toppings like salsa or jalapeños.