Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large mixing bowl, combine the cooked shredded chicken, 2 cups of shredded Mexican blend cheese, sour cream, tomatillo salsa verde, chopped green chiles, ranch dressing dip mix, and ground cumin. Stir until all the ingredients are well incorporated and creamy.
Step 3: Pour the creamy chicken mixture into a greased baking dish and spread it out evenly.
Step 4: Sprinkle the remaining ½ cup of shredded Mexican blend cheese over the top.
Step 5: Bake for about 25-30 minutes or until the cheese is melted and slightly golden.
Step 6: Remove from the oven, let cool slightly, and garnish with chopped scallions or cilantro. Serve warm with tortilla chips, pita bread, or vegetable sticks.