Goat Cheese, Leek, and Potato Galettes with Pistachio Crust

Ingredients

• 2½ cups all-purpose flour
• 1 large egg, beaten to blend
• 1 teaspoon kosher salt
• Crushed pink peppercorns and flaky sea salt (optional; for serving)
• 1 large leek, halved lengthwise, white and pale-green parts only, finely chopped
• Kosher salt, freshly ground pepper
• 1 teaspoon sugar
• 4 ounces goat cheese
• Honey (for drizzling)
• ¼ cup plus 1 tablespoon heavy cream
• 1 tablespoon olive oil, plus more for drizzling
• ½ cup shelled pistachios
• 2 large Yukon Gold potatoes, thinly sliced on a mandoline
• 1 cup (2 sticks) chilled unsalted butter, cut into pieces
• 2 garlic cloves, finely chopped
• 4 tablespoons coarsely chopped dill, plus more for serving