Step 1: Preheat the Oven

Preheat your oven to 400°F. Lightly spray a 9×13-inch baking dish with nonstick spray to prevent sticking and make cleanup easier.

Step 2: Prepare the Chicken Mixture

Heat olive oil in a medium skillet over medium heat. Add the diced onion and cook for 2-3 minutes, stirring occasionally until the onion becomes translucent and fragrant.

Stir in the shredded chicken, taco seasoning, drained diced tomatoes, and drained green chiles. Mix everything well and reduce the heat to low. Let the mixture simmer for 5-8 minutes, allowing the flavors to blend together. Stir occasionally to prevent burning.

Step 3: Crisp the Taco Shells

While the chicken mixture is simmering, place the taco shells standing up in the prepared baking dish. The shells should be positioned so they stay upright, making it easy to fill them later.

Bake the empty taco shells for 5 minutes. This step ensures that they stay crispy even after being filled with ingredients.

Step 4: Assemble the Tacos

Remove the taco shells from the oven. Spoon about 1 tablespoon of refried beans into the bottom of each shell. This adds a creamy texture and helps prevent the bottom of the shell from becoming soggy.

Fill each taco shell almost to the top with the chicken mixture, distributing it evenly among all the shells.

Generously sprinkle shredded cheese over the top of each taco. Adding more cheese creates a delicious melted topping that enhances the flavor.

Step 5: Bake the Tacos

Return the baking dish to the oven and bake for 7-10 minutes, or until the cheese is fully melted and the edges of the taco shells are golden brown.

Step 6: Add Toppings and Serve

Remove the tacos from the oven and allow them to cool slightly before adding toppings. Popular options include sliced jalapeños, sour cream, salsa, shredded lettuce, and fresh cilantro. These toppings add freshness and balance the richness of the tacos.

Serve immediately while the tacos are warm and crispy.