The people of Alsace (a French region on the border with Germany) love their rich and hearty dishes like this delicious onion tart. The onion of sliced very thin and cooked slowly until they almost ‘melt‘. Combined with cream and Gruyère cheese, this savory tart is sure to be a hit.
- 2 Tbsp vegetable oil
- 2 Tbsp unsalted butter
- 4 medium onions, cut in half and sliced as thin as possible
- 1/2 tsp granulated sugar
- Kosher salt, to taste
- Black pepper, to taste
- 3 large eggs
- 1 1/4 cups heavy cream
- 3/4 tsp salt
- 1/2 tsp black pepper
- 1/8 tsp freshly grated nutmeg
- 1/3 cup finely grated Gruyère cheese
- Prep Time: 15 minutes
- Cook Time: 75 minutes
- Total Time: 90 minutes
- Yield: Makes 1 Tart
Heat the oil and butter in a large, heavy skillet. Add the onions and sugar, season with salt and pepper, and sauté over medium-high heat, stirring frequently, until lightly browned. Lower the heat and continue to cook the onions uncovered until very soft and evenly browned, about 30 minutes. Stir frequently and watch they don’t burn. Turn down the heat, if necessary. When the onions are done, transfer them to a strainer and drain.
Heat the oven to 375°F. Butter a ceramic tart dish or metal tart pan with removable bottom. If using a pan with a removable bottom, place onto a baking sheet.
In a bowl, whisk the eggs together with the cream. Whisk in the salt, pepper, and nutmeg. Add the drained onions and half of the cheese and mix well. Fill the prepared tart shell with the onions and custard. Top with the remaining cheese and bake until the tip of a knife comes out clean and the top of the tart is puffed and brown, 40 to 45 minutes.
Let cool for at least 15 to 20 minutes before serving.