Step 1

To make the dough, in a food processor, combine the flour, yeast and sugar; pulse until combined, about 5 pulses. Add the water and 1 tablespoon oil, then process until a smooth, slightly sticky ball forms, about 30 seconds. If the mixture is dry, mix in additional water, 1 teaspoon at a time (up to 1 tablespoon total). Let rest in the food processor for 5 minutes. Meanwhile, coat a medium bowl with 1 teaspoon of the oil.

Step 2

Sprinkle the salt over the dough and process until the dough is smooth and pliable, about 1 minute. Transfer the dough to the prepared bowl and turn to coat; return the food processor bowl and blade to the base. Cover the dough with plastic wrap and let rise at room temperature until doubled, about 45 minutes.

Step 3

Meanwhile, make the filling. In the now-empty processor, combine all three cheeses and the pepper. Process until the mixture is creamy and well combined, about 1 minute, scraping the bowl about halfway through. Set aside, covered, at room temperature until ready to use. Heat the oven to 475°F with a rack in the middle position.

Step 4

When the dough has doubled, line a rimmed baking sheet with kitchen parchment. Dust the counter with flour and turn the dough out onto it. Working from the center outward, gently dimple the dough with your fingers, forming an 8-inch round with thicker edges. Transfer the dough to the baking sheet, then stretch it into a 12-inch-by-6-inch oval.

Step 5

Mound the filling on the dough and spread it in an even layer, leaving a 1½-inch border around the edges. Fold the unfilled sides onto the filling, then twist each end 3 or 4 times to form a boat shape. Brush the edges with the remaining 2 teaspoons oil. Let rise at room temperature until slightly puffy, about 20 minutes.

Step 6

Bake until the edges of the khachapuri are golden brown and the filling is bubbling and spotty brown, about 15 minutes. Using a wide metal spatula and working quickly, transfer the khachapuri to a cutting board. Immediately add the egg yolk, butter and chives (if using) to the center of the filling. Using a fork, swirl until well combined. Serve right away.

Step 7

Georgian Cheese Bread with Fresh Herbs: Follow the recipe to make the dough. While the dough is rising, in the now-empty food processor, combine 1 bunch scallions (roughly chopped), 1 cup lightly packed fresh flat-leaf parsley and ½ cup lightly packed fresh dill. Pulse until roughly chopped, about 10 pulses. Add 113 grams (1 cup) shredded whole-milk mozzarella cheese, 57 grams (½ cup) crumbled feta cheese, 60 grams (2 ounces) cream cheese (cut into 1-inch cubes) and ½ teaspoon ground black pepper. Process until the mixture is creamy, smooth and well combined, about 1 minute, scraping the bowl about halfway through. Set the filling aside, covered, at room temperature until ready to use. Continue with the recipe to shape, fill and bake the dough and add the egg yolk and butter after baking as directed.