Preheat your oven to 425 degrees and spay an 8x11 inch baking dish with vegetable oil spray. You can use a smaller baking dish if you want the lasagna to fill the dish up more.
In a small bowl, make the sauce by mixing together the yogurt, lemon juice, pico de gallo, tomato sauce, green chilis, and spices.
Place two tortillas in the baking dish, so that it is covering most of the bottom of the dish.
Spread some of the sauce on top of the tortillas so that the sauce forms a layer over the tortillas. You can be generous!
Sprinkle a third of the onions, black beans, spinach, red bell pepper, and cheese on top.
Add two more tortillas on top of the veggies, beans, and cheese.
Repeat Steps 4, 5, and 6.
Top with cheese, and any remaining sauce and veggies, and cook in the oven for 15 minutes or until the cheese is bubbling or golden brown.