In a large mixing bowl, combine the all-purpose flour and salt.
Gradually add the water and mix until a dough forms.
Knead the dough on a floured surface for about 10 minutes until smooth and elastic.
Coat the dough with vegetable oil, cover with a damp cloth, and let it rest for at least 30 minutes.
In a mixing bowl, combine the ground beef or lamb, finely chopped onion, minced garlic, ground cumin, ground coriander, salt, black pepper, and chopped fresh parsley or cilantro.
Mix well until all ingredients are thoroughly combined.
Divide the rested dough into small portions.
On a floured surface, roll each portion into a thin circle, about 3-4 inches in diameter.
Place about 1 tablespoon of the meat filling in the center of each dough circle.
Fold the dough over the filling to form a half-moon shape, then pinch the edges together to seal. You can also bring the corners together and pinch to form a pouch-like shape.
Repeat with the remaining dough and filling.
Line a steamer basket with parchment paper or lightly oil it to prevent sticking.
Arrange the filled dumplings in the steamer basket, making sure they do not touch each other.
Steam the dumplings over boiling water for about 20-25 minutes, or until the dough is cooked through and the filling is fully cooked.
In a small bowl, combine the plain yogurt, minced garlic, and salt. Mix well.
Arrange the steamed mantu on a serving plate.
Drizzle with the yogurt sauce.
Garnish with chopped fresh parsley or cilantro and a sprinkle of paprika or cayenne pepper if desired.
Enjoy your meal!