Kayseri Mantısı (Kayseri-Style Dumplings)

To make the dough:

1. In a large bowl, combine the flour and salt.
2. Add the egg, then slowly add just enough water to bring together a dough while mixing.
3. On a lightly floured surface, knead the dough until soft and smooth.
4. If too crumbly to come together, slowly add a little more water. If too sticky to handle, slowly add a little more flour.
5. Wrap the dough in plastic or cover and allow to rest at room temperature for 30 minutes.

To make the filling:

1. In a large bowl, mix together the ground beef, onion, salt, pepper, parsley, and optionally red pepper flakes until evenly combined. Cover and refrigerate until ready to use.

To assemble:

1. Line a rimmed baking sheet with parchment paper and lightly dust with flour. Set aside.
2. Break off a small piece of the rested dough, keeping the remainder covered, and place on a lightly floured work surface.
3. Roll the dough into a thin sheet.
4. Cut the thin sheet into 1/2-1 inch (1.25-2.5 centimeter) squares.
5. Place small dots of the filling in the center of each square.
6. Bring up two opposite corners of the square over the filling and pinch together at the top.
7. Bring up the other two opposite corners of the square over the top and pinch together to enclose the filling.
8. Place the dumpling on the parchment-lined baking sheet and repeat with remaining pieces, then remaining dough and filling.
9. If not cooking immediately, place the baking sheet in the freezer. Once the dumplings are frozen, transfer to a freezer-safe bag and freeze for up to 2 months.

To cook:

1. Place the yogurt in a medium bowl. Fold in the garlic and salt until combined and set aside.
2. Bring a large pot of salted water to a boil. Reduce to a simmer and cook the formed dumplings, stirring occasionally to prevent sticking, until tender, about 10-15 minutes.
3. While the dumplings are simmering, place the butter in a small saucepan over medium low heat.
4. Once melted, whisk in the tomato paste and continue to cook for another 2 minutes, until evenly combined and heated through.

To serve:

1. One way to serve the Mantı is to drain the tender dumplings, transfer to individual bowls, then top with the garlic yogurt, a drizzle of the tomato butter, and a sprinkling of dried mint and sumac. Serve immediately.
2. Another way to serve the Mantı is to stir the tomato butter into the simmering water with the dumplings. Use a ladle to transfer the dumplings with some of the tomato butter water to a bowl. Top with the garlic yogurt and a sprinkling of dried mint and sumac before serving immediately.