Ingredients

3 teaspoons butter
1 small onion, chopped
2 tablespoons Dijon mustard
10-ounce package frozen chopped spinach, thawed, squeezed dry
Salt and pepper
4 eggs
1/4 teaspoon ground nutmeg
1 cup packed Gruyere cheese

Directions

Melt 2 teaspoons of the butter in heavy medium skillet over medium heat. Add onion; saute until soft and beginning to brown, about 10 minutes. Mix in mustard, then spinach. Season filling with salt and pepper; stir until heated through.

Preheat broiler. Beat eggs and nutmeg in small bowl to blend. Mix in half of the cheese. Melt remaining 1 teaspoon butter in medium nonstick skillet over medium-high heat. Pour egg mixture into skillet and cook until almost set in center, occasionally lifting edges and letting uncooked egg mixture flow underneath, about 4 minutes. Spoon filling over half of omelet; fold other half over. Sprinkle remaining cheese over omelet. Broil until cheese melts, about 1 minute. Makes 2 servings. Recipe can be doubled.