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 lamb or beef, finely chopped onion, minced garlic, ground cumin, ground coriander, salt, black pepper, and chopped fresh cilantro or parsley (if using).
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 or square, about 4-5 inches in diameter.
Place a spoonful of the meat filling in the center of each dough circle or square.
Fold the dough over the filling to form a triangle or square, sealing the edges by pinching them together. You can also use a fork to crimp the edges for a decorative seal.
Preheat your oven to 375°F (190°C).
Place the filled samsas on a baking sheet lined with parchment paper.
Brush the tops of the samsas with the beaten egg and sprinkle with sesame seeds if desired.
Bake in the preheated oven for about 25-30 minutes, or until the samsas are golden brown and the filling is cooked through.
Allow the samsas to cool slightly before serving.
Enjoy your meal!