Preheat oven to 375 degrees F. Spoon about a quarter cup of the salsa verde in a rectangular casserole dish. Lay two of the tortillas side by side in the dish. Spread some of the pumpkin on each tortilla, and then spoon an even layer of beans over top. Pour a quarter cup of the salsa verde over top.
Lay another tortilla on top and repeat until each stack has three tortillas. Top each with remaining salsa verde over each stack and then sprinkle the cheese over top. Bake for 10-15 minutes, until cheese is melted.
Serve topped with the sour cream and green onions with the lime wedges on the side.