Shredded Chicken-Enchilada Casserole

Shredded Chicken-Enchilada Casserole

 Ingredients: 2 spray(s) cooking spray1 1/2 Tbsp olive oil3 cup(s), chopped uncooked onion(s), divided1 pound(s) cremini mushroom(s), sliced 1/4-in thick2 medium uncooked zucchini, halved lengthwise, sliced 1/4-in thick1 1/2 tsp table salt, divided28 oz…