Preheat your oven to 400°F.

Prepare your mise en place: measure out the milk, chicken broth, and room temperature sour cream. Finely chop the green chilis, thinly slice the green onions, and have the cooked shredded chicken and frozen corn measured and ready.

Melt the butter in a medium saucepan over medium heat. Once melted, whisk in the flour and cook for about 1 minute, stirring constantly to create a light roux.

Gradually whisk in the milk and chicken broth together, then add the sour cream, whisking constantly until completely smooth to avoid lumps.

Add the cumin, finely chopped green chilis, chili powder, salt, and black pepper to the saucepan. Reduce heat to medium-low and simmer for 3-5 minutes, stirring occasionally, until the sauce thickens enough to lightly coat the back of a spoon.

In a medium bowl, combine the cooked shredded chicken, frozen corn, and sliced green onions. Pour the warm sauce over the chicken mixture and stir until everything is evenly coated.

Warm the corn tortillas in a dry skillet over medium-low heat, about 30 seconds per side, until pliable and warm.

Place a warmed tortilla on your work surface, add about 3 tablespoons of the chicken filling down the center, sprinkle with about 1/2 ounce of shredded mozzarella cheese, then fold the tortilla in half. Arrange the filled tacos seam-side up on a parchment-lined baking sheet.

Bake for 12-15 minutes, until the cheese is melted and bubbly and the tortillas have begun to turn golden brown around the edges.

Remove from the oven and let cool for 1-2 minutes before serving.