Directions

1. 1

   Preheat your oven's broiler to low. Line a baking sheet with parchment paper or aluminum foil; if using foil, lightly spray it with non-stick cooking spray. Arrange the tomatillos, serrano chiles, diced onion, and minced garlic cloves on the prepared sheet in a single layer.

2. 2

   Place the baking sheet in the oven and broil on low for 5-7 minutes. Flip each piece over and continue broiling for another 3-5 minutes, until the vegetables are charred and beginning to burst open. The tomatillos should release their juices; do not let them burn completely.

3. 3

   Carefully transfer the charred tomatillos, onion, garlic, and chiles to a food processor or blender. Pulse until the mixture is finely chopped. Add a small amount of the pan juices if needed to achieve a thick, pourable sauce consistency. Season with salt to taste and set the tomatillo sauce aside.

4. 4

   Increase oven temperature to 400°F. Line a separate baking sheet with parchment paper and brush the surface lightly with olive oil.

5. 5

   Lay 6 of the corn tortillas on the oiled baking sheet, spacing them evenly. Brush the tops of the tortillas with a light coating of olive oil.

6. 6

   Bake the tortillas for about 10 minutes, or until they are golden and crispy. Transfer them to a cooling rack, then repeat the same process with the remaining 6 tortillas. Set all the crispy tortillas aside.

7. 7

   While the tortillas are crisping, heat a large skillet over medium-high heat. Add 1 tablespoon of olive oil and let it heat for 15-30 seconds until it is shimmering.

8. 8

   Add the diced onion and bell pepper to the hot oil. Season generously with salt and cook, stirring frequently, for about 4 minutes, until the onion becomes translucent and begins to soften. Lower the heat if needed to prevent burning.

9. 9

   Stir in the minced garlic and cook for 30-60 seconds until fragrant. Add the diced zucchini and corn. Continue cooking for about 3 minutes more, stirring occasionally, until all vegetables are just tender. Transfer the mixture to a bowl and set aside.

10. 10

    Add the remaining 1 tablespoon of olive oil to the same skillet over medium-high heat. Once shimmering, add the sliced cremini mushrooms.

11. 11

    Cook the mushrooms, stirring frequently, for about 6 minutes, until they begin to brown and release their moisture. Add a splash of water if needed to prevent sticking.

12. 12

    Return the reserved vegetable mixture to the skillet with the mushrooms. Stir well to combine. Remove from heat and keep warm until you are ready to assemble the stacks.

13. 13

    To assemble the stacks, arrange 4 of the crispy tortillas on a baking sheet lined with parchment paper or foil. On each tortilla, layer about 1/3 cup of the vegetable-mushroom mixture, followed by 1-2 tablespoons of the roasted tomatillo sauce and 1/4 cup of shredded cheese.

14. 14

    Place another crispy tortilla on top of each stack. Layer with another 1/3 cup of vegetables, 1-2 tablespoons of tomatillo sauce, and 1/4 cup of cheese.

15. 15

    Top each stack with a third crispy tortilla. Drizzle the top of each stack with about 1 tablespoon of remaining tomatillo sauce and sprinkle with 1/4 cup of the remaining shredded cheese.

16. 16

    Bake the assembled stacks at 400°F for 15-20 minutes, until the cheese is melted and bubbly and the edges are golden brown.

17. 17

    Remove from the oven and garnish each stack generously with fresh cilantro. Serve immediately while the cheese is warm and the tortillas are crispy.