Sorrel-Onion Tart

• 1 recipe
• 4 tablespoons butter, in all
• 1 large red onion, thinly sliced
• 1/2 teaspoon salt
• 4 to 8 ounces sorrel leaves
• 2 large eggs
• 1 cup heavy cream
• 2 ounces Gruyere cheese, grated
• Pepper

1. Prepare the tart dough, partially prebake it, and set it aside.
2. Melt 3 tablespoons of the butter in a wide pan, add the onion and the salt. Cover the pan, and stew slowly until the onion is completely soft, about 10 minutes. Check it occasionally and give it a stir.
3. While the onion is cooking, cut off the stems of the sorrel leaves and roughly slice the leaves. Melt the remaining tablespoon of butter in a pan, and add the sorrel by large handfuls. Although the amount of leaves will seem voluminous, they will quickly cook down to almost nothing. Cook over a low heat until they have wilted and turned a grayish-green color, 3 to 4 minutes.
4. Whisk the eggs with the cream; then stir in the onion, sorrel, and half of the cheese. Taste for salt, and season with freshly ground black pepper.
5. Preheat the oven to 375u0b0F. Distribute the remaining cheese over the crust; then pour the filling on top. Bake in the center of the oven until the custard is set and well colored, about 35 to 40 minutes. Serve the tart while it is hot. For wine, consider serving a chardonnay or French white Burgundy.
6. This tart is based on a recipe from Richard Olney's
7. .

recipe, butter, red onion, salt, sorrel leaves, eggs, heavy cream, gruyuere cheese, pepper

Taken from www.epicurious.com/recipes/food/views/sorrel-onion-tart-368509 (may not work)