1. For 6 servings, in medium bowl, beat together 4 eggs, 1/2 cup sugar, 1 1/2 teaspoons vanilla and 1/4 teaspoon salt, if desired, until well blended.
2. Stir in 3 cups skim or 1% low-fat milk, heated until very hot.
3. Place 6 lightly greased 6-ounce custard cups or 1 lightly greased 1 1/2-quart casserole in large baking pan. Pour egg mixture into cups or casserole.
4. Sprinkle with ground nutmeg or cinnamon, if desired. Place pan on rack in preheated 350° F oven. Pour very hot water into pan to within 1/2 inch of top of cups or 1 inch of top of casserole.
5. Bake until knife inserted near center comes out clean, about 25 to 30 minutes for cups or about 35 to 40 minutes for casserole. Remove promptly from hot water. Cool on wire rack about 5 to 10 minutes. Serve warm or refrigerate and chill thoroughly to serve cold.
