Ingredients

• • 1 recipe Mama’s Butter Piecrust (or store bought pie crust)
• • 4 tablespoons (½ stick) butter
• • 3 pounds Vidalia onions (or other sweet variety such as Walla-Walla and Texas 1015), cut in half and thinly sliced
• • 1 teaspoon minced garlic
• • Kosher salt
• • ¼ teaspoon freshly ground black pepper
• • 1½ tablespoons Dijon mustard
• • Optional: 1½ teaspoons fresh thyme leaves
• • 1 cup grated Parmesan cheese
• • 1 egg, beaten
• • Optional: 4 slices bacon, cooked, drained, and chopped

Instructions

1. Preheat the oven to 400°F.
2. Roll out the dough to a 12 inch circle. Place the dough on a baking sheet lined with parchment paper.
3. Melt the butter in a large skillet on low heat. Add the onions and stir to coat with the butter. After 5 minutes, add the garlic. Continue to cook the onions, stirring occasionally. In 20 minutes, the onions will soften and shrink in the pan. In 30 to 40 minutes, they will be golden brown.
4. Season with salt to taste and the pepper. Stir in the mustard and the thyme, if using.
5. Sprinkle the crust with 1/3 cup of the Parmesan. Pile the onions in the center and spread to within 2 inches of the edge. Fold the dough up to and over the onions, pleating it as necessary. Brush the crust with the egg.
6. Place in the oven. Check after 10 to 15 minutes. When the crust begins to color, sprinkle the top with the remaining 2/3 cup Parmesan and the bacon, if using. Bake 10 to 15 minutes more. Put the oven rack in the top position. Turn on the broiler and broil 3 to 5 minutes, until deeply brown. Watch carefully, as ovens vary in broiling intensity.