Black bean, roasted pepper, spinach, and tortilla casserole recipe

I have a long list of recipes that I'm dying to try, and this one has been near the top of the list since I first saw it in December.  I've almost made it on several occasions, but something always foiled my plans.  The time finally arrived, though, and I'm glad that it did.  Sometimes if I wait too long to make a recipe, I'll build it up too much in my head and then it can't live up to my expectations.  However, this one didn't disappoint.  I loved the mix of ingredients, particularly the beans, spinach, and roasted peppers, and the salsa and yogurt gave it a hint of a tangy flavor.  There was just enough cheese to help hold it together without being overpowering and greasy.  It was also nice to pull out my spring-form pan for the first time in 4 years (The last thing I attempted to make with it was a sugarfree cheesecake.  BAD IDEA.  That thing made its way into the trashcan in a heartbeat.  Now I have better memories to associate with the pan.)

Black bean, roasted pepper, spinach, and tortilla casserole (adapted from lisa is cooking)
(Printable version)

4 poblano peppers
18 corn tortillas, cut in half
10 oz spinach (fresh or frozen)
1 Tbsp olive oil
1 onion, chopped
3 garlic cloves, minced
3 cups cooked black beans (or 2 cans)
1 cup plain yogurt
2 cups salsa verde
4 oz. shredded cheddar cheese
3 green onions (green part only), chopped

Place the peppers on a baking sheet and roast at 500 for about 10 min, or until the top is very blistered, and then turn and cook for another 10 min.  Then put the peppers in a paper bag, close the bag, and let sit for 10 min.  Finally, remove the skin and seeds from the peppers and chop them well.

While the peppers are resting, place the tortilla halves on two baking sheets, mist them with olive oil, and bake for 6 minutes at 425.  Then set them aside while you prepare the remaining ingredients.

If using fresh spinach, rinse it and then place it in a large skillet and cook just until wilted, then set the spinach aside.  If using frozen spinach, cook it according to the package directions.  Next, heat the oil over medium heat in the sauce pan, add onions, and cook until tender.  Then stir in the chopped poblanos and cook for a couple of minutes.  Set this mixture aside.  Add more oil to the pan if necessary, and then stir in the garlic, cook for a minute, and add the beans.

Place a spring-form pan (I used 8 1/2" pan, but bigger is better) on a baking sheet, and spray the bottom and sides with olive oil.  Layer 12 tortilla halves on the bottom of the pan, and then add the poblano mixture, half of the bean mixture, 1/2 cup yogurt, 2/3 cup salsa, and 1/2 cup cheese.  Repeat these layers substituting the spinach for the poblanos.  Then top with the remaining tortillas, salsa, and cheese, and top with green onions.  Bake at 350 for about 45 minutes, then let cool for 15 minutes before removing the ring of the pan.  Serves 6-8.