Ingredients

Dough

• 455 grams (3 1/2 C) unbleached all purpose flour
• 2 1/4 tsp instant yeast
• 1 tsp sugar
• 1 1/4 tsp salt
• 1/2 cup water
• 1/4 cup milk
• 1/4 cup vegetable oil
• 2 large eggs
• 2 large egg yolks

Filling and Topping

• 1 tbsp butter
• 1 tbsp olive oil
• 1 large red onion, halved and thinly sliced
• 6 large shallots, thinly sliced
• 1 tsp sugar
• 1 tbsp herbes de Provence, plus more for sprinkling (mine is from The Spice House)
• 6 ounces grated Gruyere cheese, plus another ounce for sprinkling
• 1 tbsp Dijon mustard
• 1 egg, beaten with 1 T water

Instructions

1. Whisk the dry ingredients of the bread in the bowl of a stand mixer.
2. Whisk the water, milk, eggs, and egg whites together in a bowl and add to the dry ingredients.
3. Mix with the dough hook for about 10 minutes on medium low speed.
4. Place the dough into an oiled bowl, cover, and allow to rise until doubled, about an hour.
5. While the dough is rising, prepare the onion filling. In a 12 inch skillet, melt the butter and olive oil.
6. Add the onions, shallots, and sugar, and cook for about 5 minutes on medium heat. Add the herbs and continue to cook, stirring regularly, for about 20 minutes more, until caramelized.
7. When the dough has doubled, place it on a piece of baking sheet sized piece of parchment paper.
8. Roll it out to a 12 inch by 11 inch rectangle.
9. Spread the mustard lengthwise in the middle of the dough into a 3 inch line.
10. Spread the onion mixture over the mustard.
11. Sprinkle the 6 ounces of cheese over the onion mixture.
12. Using a sharp knife, make diagonal 1 inch cuts on both sides of the stripe of onion and cheese mixture.
13. Lift the parchment with the loaf onto a baking sheet.
14. Fold the ends over the filling, and then fold the strips over the filling, alternating from both sides, so that the top of the dough looks like a braid.
15. Preheat the oven to 350 degrees F.
16. Cover the loaf loosely with oiled plastic wrap and let it rise until doubled, about 30 to 40 minutes.
17. Brush the top of the loaf with the egg wash.
18. Sprinkle the center of the braid with about an ounce of grated Gruyere.
19. Sprinkle the top of the cheese lightly with herbes de Provence.
20. Bake the loaf for about 45 minutes, until nicely browned and the center registers about 190 degrees F.
21. Cool on a wire rack. Serve warm, or cool completely and wrap in foil to serve later.