Adapted from a Cooking Light recipe
Rich & creamy without the addition of butter or cream.
Preheat oven to 400°F.
Combine first 4 ingredients in a large saucepan over medium heat; bring to a boil, stirring constantly. Reduce heat; simmer 10 minutes, stirring frequently. Remove from heat, and let stand 10 minutes. Drain potatoes in a colander over a heatproof bowl, reserving 1 cup milk mixture. (If necessary, add additional milk to the mixture so that you have a full cup.) Discard bay leaves.
Cook haricots verts in boiling water for 2 minutes or until crisp-tender. (If using green beans, cook for 4 minutes until crisp-tender.) Rinse in cold water; drain.
Arrange half of the potatoes in the bottom of a 13 x 9-inch baking dish coated with cooking spray. Arrange haricots verts and ham over potatoes. Sprinkle with half of cheese, salt, and pepper. Top with the remaining potatoes. Sprinkle with the remaining cheese, salt, and pepper. Stir nutmeg into reserved milk mixture; pour over potatoes.
Cover with foil; cut 3 (1-inch) slits in foil. Bake at 400° for 20 minutes. Uncover and bake an additional 20 minutes or until cheese begins to brown. Let stand 10 minutes before serving.