Galette with Greens, Gruyere, and Pancetta | Saveur

Ingredients

• 1 cup plus 2 Tbsp. all-purpose flour, plus more for dusting
• 1 1⁄2 tsp. sugar
• 1⁄2 tsp. kosher salt
• 6 tbsp. (3 oz.) chilled unsalted butter, cut in small cubes
• 4 oz. pancetta, cut in ⅓-inch cubes (¾ cup)
• 1 tbsp. extra-virgin olive oil
• 5 medium shallots, finely diced (1 cup plus 2 Tbsp.)
• Kosher salt
• 4 oz. Tuscan kale, chopped in 1-inch pieces (6 cups)
• 2 oz. mustard greens, chopped in 1-inch pieces (2 cups)
• 5 medium garlic cloves, minced (3 Tbsp.)
• 1 cup crème fraiche (8 oz.)
• 2 tbsp. dijon mustard
• 5 oz. gruyère cheese, coarsely grated (1½ cups)
• 1 large egg, beaten with 1 tsp. cold water