Red Onion and Mushroom Casserole

LAYERED YAMS, RED ONION AND MUSHROOM CASSEROLE2 medium sized yams, leave peel on2 red onions, sliced1 (8-oz.) package of sliced baby portabella mushroomsOlive oilSalt, black pepperGround cuminBalsamic vinegar In 9x11” baking dish, spray with PAM.Slice the yams about ½” thick…