In a skillet, heat olive oil over medium heat. Sauté the chopped onion and minced garlic until softened and fragrant, about 3-4 minutes.
In a large bowl, combine the shredded chicken, sautéed onion and garlic, cottage cheese, Greek yogurt, ground cumin, chili powder, salt, and black pepper. Mix well until all ingredients are fully incorporated.
In a separate saucepan, add the chicken broth and bring to a simmer. Gradually add half of the shredded mozzarella cheese, stirring until melted and combined to create a creamy sauce.
Lightly spray a 9x13-inch baking dish with cooking spray.
To assemble the enchiladas, warm the corn tortillas slightly in a microwave to make them pliable. Place 2-3 tablespoons of the chicken mixture along the center of each tortilla, adding a little chopped spinach on top. Roll up tightly and place seam-side down in the baking dish.
Once all enchiladas are assembled, pour the creamy white sauce over the top, covering them completely. Sprinkle the remaining shredded mozzarella on top.
Bake in the preheated oven for 25-30 minutes or until the cheese is bubbly and slightly golden.
Remove from the oven and let cool slightly before serving. Garnish with freshly chopped cilantro.