Baked Eggs with Tarragon and Leeks

Why I Love This Recipe
I love preparing this right after dinner - my breakfast is all ready for the am. It's a great company dish too for brunch or for overnight guests.
Ingredients You'll Need
3 tablespoons unsalted butter
3 large leeks, white and pale green only -- coarsely chopped (3 to 4 leeks)
1 1/2 cups shredded Gruyère cheese
1/2 cup grated Parmesan cheese
8 large Fresh Eggs
2 cups whipping cream
2 tablespoons plus 2 teaspoons fresh tarragon -- chopped
Ground pepper -- to taste
Directions
Preheat oven to 375º. Grease a 9" × 13" glass baking dish. In butter, sauté leeks until tender. Spread in bottom of baking dish. Mix cheese and spread all but 1/2 cup over the leeks. Whisk together eggs, cream, tarragon and pepper. Pour into dish. (At this point, dish can be refrigerated overnight). Bake for 30 minutes until top is golden brown and center is set. Sprinkle with remaining 1/2 cup cheese and return to oven until cheese melts.