Hot Dog Vol-Au-Vents (Saucisson En Croute)

• 0.5 (11 ounce) box frozen puff pastry, thawed but cold (1 sheet)
• 1 tablespoon canola oil
• 1 1/2 yellow onions, finely sliced on a mandoline
• 3/8 teaspoon granulated sugar
• kosher salt
• 1 tablespoon Dijon mustard
• 4 hot dogs, each cut into thirds
• 1 egg, beaten with a splash of water
• poppy seed
• fleur de sel

1. Thaw the puff pastry in the refrigerator overnight.
2. Preheat the oven to 400u0b0F Heat the canola oil in a wide skillet over medium heat. When it shimmers, add the onions, sugar, and salt. Saute, stirring often, until the onions are golden and soft, 8-10 minutes. While they are cooking, add 1 tablespoon of water whenever the bottom of the pot gets brown. When they are ready, drain any extra oil or liquid and transfer the onions to a bowl. Stir in mustard.
3. Cut the puff pastry in 1 1/2-inch strips (a pizza wheel is excellent for this - use a ruler to keep the lines straight), then cut each strip in half the short way. Spread some of the onion-mustard mixture on each strip, and roll each strip around 1 piece of hot dog. Place seam-side-down on a rimmed baking sheet, leaving space for the pastry to puff. Repeat with the remaining pastry, onion mixture, and hot dogs.
4. Use a pastry brush to lightly brush each piece with egg wash. Sprinkle with poppy seeds and a touch of fleur de sel. Bake until puffed, golden, and crisp, 22 to 25 minutes. Serve right out of the oven.

pastry, canola oil, yellow onions, granulated sugar, kosher salt, mustard, hot dogs, egg, fleur de sel

Taken from www.food.com/recipe/hot-dog-vol-au-vents-saucisson-en-croute-452411 (may not work)