Tortilla cups baked in a muffin tin are filled with a healthy and delicious mix of mushrooms, spinach, avocado and cheese.
Preheat oven to 450 degrees. In a large skillet, heat oil over medium. Add onion and cook 3 minutes. Increase heat to medium-high, add mushrooms, and saute until golden, 5 to 8 minutes. Transfer to a large bowl, toss with spinach and 1 cup pepper Jack, and season with salt and pepper.
Lightly coat 6 jumbo muffin cups with cooking spray and press tortillas into cups. Divide vegetable mixture among cups and top with remaining 1/2 cup pepper Jack. Bake until cheese is melted and tortillas are light golden and crisp, about 7 minutes. Serve tortilla cups topped with avocado.