6 to 8 green onions, coarsely chopped
1/4 cup unsalted butter
1-1/2 cups (6 ounces) shredded Gruyere or Swiss cheese
1/2 cup freshly grated Parmesan cheese
8 large eggs
2 cups whipping cream
2 tablespoons plus 2 teaspoons chopped fresh tarragon
1/2 teaspoon salt
1/3 teaspoon freshly ground pepper
Additional sprigs of fresh tarragon for garnish, if desired
Saute chopped onions in butter in a medium skillet over medium heat, stirring constantly, until tender. Spoon into a lightly greased 13 x 9 x 2-inch baking dish.
Combine cheeses, reserving 1/2 cup cheese mixture for topping. Sprinkle remaining cheese mixture over leeks.
Combine eggs, whipping cream, tarragon, salt and pepper in a bowl, stirring with a wire whisk until blended. Pour egg mixture over leek mixture.
Bake, uncovered, at 375*F (190*C) for 30 minutes or until set and lightly browned. Sprinkle with reserved cheese mixture; bake and additional 5 minutes or until cheeses melt. Garnish, if desired. Serve immediately.
Makes 8 to 10 servings.