Prepare the dough: In a large mixing bowl, combine the flour and salt. Gradually add the warm water and knead until a smooth dough forms. The dough should be soft and elastic, but not sticky. Add the vegetable oil and knead for a few more minutes until fully combined. Cover the dough with a damp cloth and let it rest for about 30 minutes.

1. Prepare the filling: While the dough is resting, heat the vegetable oil in a skillet over medium heat. Add the chopped onion and garlic, cooking for 3-4 minutes until they are softened and fragrant. Set aside to cool slightly. In a large bowl, combine the ground meat, sautéed onion and garlic, soy sauce (if using), black pepper, and salt. Mix thoroughly to combine all ingredients. If the filling is too dry, you can add a little water to help bind it.
2. Shape the dumplings: Once the dough has rested, divide it into small balls, about 1-inch in diameter. Roll each ball into a small circle, about 3 inches wide. Place a spoonful of the filling in the center of each dough circle. Pinch the edges of the dough together to seal the dumpling, forming small pouches or half-moon shapes. You can pleat the edges for a traditional look or simply fold them over to seal. Be sure that the filling is securely enclosed.
3. Steam the Buuz: Fill a steamer or large pot with water and bring it to a boil. Grease the steamer basket or use parchment paper to prevent sticking. Arrange the prepared Buuz in the basket, leaving some space between each dumpling for expansion during steaming. Steam the Buuz for 15-20 minutes or until the dough becomes tender and the filling is fully cooked. The Buuz should be soft and slightly translucent once done.
4. Serve: Once the Buuz are steamed, carefully remove them from the steamer and serve hot. Buuz is traditionally enjoyed with a side of pickles or fresh vegetables. In Mongolia, it is commonly served with hot tea (especially milk tea) for a comforting, fulfilling meal.