Caramelized Vidalia Onion Galette

Ingredients

  • 1 recipe Mama’s Butter Piecrust
  • 4 tbsp. butter
  • 3 lb Vidalia onions, cut in half and thinly sliced
  • 1 tsp. minced garlic
  • Kosher salt
  • 1/4 tsp. freshly ground black pepper
  • 1 1/2 tbsp. Dijon mustard
  • Optional: 1 1/2 teaspoons fresh thyme leaves
  • 1 c grated parmesan cheese
  • 1 egg, beaten
  • Optional: 4 slices bacon, cooked, drained, and chopped

Mama's Butter Piecrust:

  • 2 1/4 c flour or 2 cups AP flour
  • 1/3 tsp. kosher salt
  • 12 tbsp. (1 1/2 sticks) cold butter, cut in small cubes
  • 5 to 7 tablespoons ice water

Instructions

Mama's Butter Piecrust:

  1. Mix the flour and the salt. Add the butter and work into the flour with your fingertips just like making biscuits until the mixture has the consistency of grated Parmesan cheese. Mix in the cold water by the tablespoon with your fingers until the dough holds together in a rough ball.
  2. Flour a sheet of waxed paper or parchment paper. Dump out the dough onto the paper. Flour the top of the dough and cover with another sheet of paper. Place the whole dough “sandwich” on a baking sheet. Refrigerate 2 hours or overnight.
  3. Remove from fridge and leave out for 30 minutes, keeping the dough sandwiched in the paper.

Onion Galette:

  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 10-15 minutes. When the crust begins to color, sprinkle the top with the remaining 2/3 cup Parmesan and the bacon, if using. Bake 10-15 minutes more. Put the oven rack in the top position. Turn on the broiler and broil 3-5 minutes, until deeply brown. Watch carefully, as ovens vary in broiling intensity.