Step 1: Prepare Your Oven. Begin by preheating your oven to 350°F (180°C). This ensures it’s ready to perfectly bake your enchiladas to gooey, bubbling perfection once assembled.

Step 2: Spinach Preparation. If you’re using fresh baby spinach, bring a large saucepan of lightly salted water to a rolling boil over high heat. Add the spinach and cook quickly, just until it’s wilted but retains its vibrant green color, typically 1 to 3 minutes. Promptly drain the spinach and rinse it thoroughly under cold running water to stop the cooking process and preserve its color. Drain it again very well, then squeeze out as much liquid as humanly possible – this is crucial to prevent a watery filling. Finally, pat it completely dry with paper towels and coarsely chop it. If you’re opting for frozen chopped spinach, place the thawed spinach in a colander set over the sink. Squeeze out all excess liquid, then pat it thoroughly dry. The drier the spinach, the better your filling will be.

Step 3: Sauté Aromatics. In your 12-inch (30-cm) ovenproof skillet (the same one you’ll finish the dish in!), warm 1 tablespoon of olive oil over medium-high heat. Add the diced yellow onion and minced garlic. Season with a pinch of kosher salt and freshly ground black pepper. Cook, stirring occasionally, until the onion becomes translucent and softened, which usually takes about 4 to 6 minutes. This step builds the foundational flavor of your filling. Once cooked, remove the skillet from heat and let the onion mixture cool slightly.

Step 4: Create the Enchilada Filling. In a large mixing bowl, combine the cooled onion and garlic mixture, the thoroughly dried and chopped spinach, the shredded cooked chicken, sour cream, half of the shredded mozzarella cheese, half of the shredded white Cheddar, half of the shredded yellow Cheddar, and all of the chopped fresh cilantro. Mix everything together until well combined. This is your delicious, creamy, and flavorful enchilada filling.

Step 5: Prepare Tortillas for Rolling. This step depends on your tortilla choice. If you’re using corn tortillas, they can sometimes be brittle and tear easily when cold. To make them pliable, wrap the stack of tortillas tightly in aluminum foil and warm them in the preheated oven for about 5 minutes. This steaming action makes them soft and flexible, perfect for rolling without cracking. If you’re using flour tortillas, there’s generally no need to warm them beforehand; you can simply proceed with the recipe as they are naturally more pliable.

Step 6: Prep the Skillet and Sauce. Briefly wipe out the skillet you used for the aromatics (if needed) and lightly slick it with just enough olive oil to coat the bottom. Spread 1 cup of the green enchilada sauce evenly across the bottom of the skillet. Pour the remaining 2 cups of enchilada sauce into a shallow pie plate or a wide, shallow bowl. This will be used for dipping your tortillas.

Step 7: Assemble the Enchiladas. Using tongs, carefully dip one tortilla into the enchilada sauce in the shallow dish, coating both sides. This softens the tortilla further and infuses it with flavor. Place the sauced tortilla on a clean work surface. Spoon a few generous tablespoons of your prepared chicken filling along the center of the tortilla. Roll it up tightly but gently. Place the rolled enchilada, seam side down, into the prepared skillet. Repeat this process with the remaining tortillas and filling, arranging them snugly side-by-side in the skillet until it’s full. Depending on your tortilla size and how generously you fill them, you’ll typically fit 6 to 8 enchiladas.

Step 8: Top and Finish. Once all enchiladas are neatly arranged in the skillet, drizzle any remaining enchilada sauce (including any left in the pie dish from dipping) evenly over the top. Then, generously sprinkle the remaining mozzarella, white Cheddar, and yellow Cheddar cheeses over the enchiladas. This three-cheese topping will create a beautiful, bubbling crust.

Step 9: Bake to Perfection. Carefully transfer the skillet to your preheated oven. Bake for 30 to 35 minutes, or until the cheese is gloriously melted and bubbly, and the sauce is gently simmering around the edges. The internal temperature of the enchiladas should be hot throughout. Once baked, remove the skillet from the oven.

Step 10: Garnish and Serve. Allow the enchiladas to rest for a few minutes before serving to let the flavors meld and the cheese set slightly. Garnish generously with the thinly sliced scallions and extra fresh cilantro. Serve these magnificent Skillet Chicken Enchiladas hot and enjoy your effortless, flavorful meal!