In bowl, stir together soup, onion, chilies, hot sauce, nutmeg and black pepper. In another bowl, use half the soup mixture, spinach, fish and 1 cup cheese; set aside.
Wrap tortillas in paper towel, microwave 30-60 seconds. Place 1/3 cup fish mixture in each tortilla, roll up. Place seam side down in greased 9x13 inch pan. Stir milk into remaining soup mixture. Pour over enchiladas. Cover, bake in 400 degree oven for 12-14 minutes. Sprinkle with remaining cheese. Let stand 40 minutes. 510 calories.