You need to start a day ahead, as the onion puree must be cold for the final preparation. Pierre Castagne’s Onion Pie is the perfect French bistro-style tart and makes a wonderful appetizer, lunch, or brunch dish.
- Onions - 5, jumbo, cut in rings
- Butter - 1 tablespoon
- Pie Shell
- Puff Pastry - 3/4 pound
- Heavy (whipping) cream - 2/3 cup
- Whole Eggs - 5
- Salt and freshly ground black pepper to taste
- Parsley - 1 sprig, stemmed and chopped
- Bibb lettuce - 1, cleaned
- Tomato - 1 large, stemmed and cut into thin vertical slices
To make the onion puree: Place the onions and butter in a covered saucepan and put over medium heat. Cook for 15 minutes, remove the cover, and turn the heat to medium-high to reduce the liquid. Cook for 10 minutes, until the onions are the color of blond caramel and the liquid has cooked away. Remove from heat and cool completely. Cover and chill overnight.
To make the pie shell: Roll the puff pastry out on a floured board until it is 1/8-inch thick and 11 - 12 inches across. Roll up on the rolling pin, place on a 9-inch fluted tart pan with remove, and unroll across the pan. Press into the pan: place your knuckle against the pastry at the base of the side, and press, then press the sides into place, and trim flat across the top. Trim any excess from the rim. Prick the crust lightly with the tip of a knife or a fork.
To finish: Preheat the oven to 450 F or highest setting. In a medium bowl, blend the cold onion puree with the heavy cream and eggs. Stir in the seasonings and parsley. Pour the mixture into the pie shell and place the oven. Cook 10 to 15 minutes, until the top is golden brown and a knife inserted in the center comes out clean. Remove from oven and let cool. Remove the pan and cut into 8 slices. Serve each with Bibb lettuce leaves and a thin slice of tomato.