The most important part of this recipe is the layered dough, achieved through folding and butter, similar to puff pastry, to make the Samsa flaky after baking. The filling must be as juicy as possible, which is ensured by a large amount of onion.
Knead a stiff but elastic dough from flour, lukewarm water, and salt. Let it rest for 30 minutes.
Roll the dough into a large, thin rectangular sheet.
Brush the sheet with 3/4 of the melted butter/margarine.
Roll it tightly into a long cylinder (like a roulade). Cut the cylinder in half, wrap it in foil, and place it in the freezer for 15 minutes (or the refrigerator for 30 minutes).
Mix the meat and onion (and fat, if using) in a bowl. The filling should be juicy.
Add salt, black pepper, and whole cumin. Mix the filling and let it rest while the dough finishes.
Remove the dough cylinders and cut them into slices about 2 cm thick (this will yield 12-14 pieces).
Roll each piece of dough into a circle (the edges should be thinner than the center). The layering should be visible.
Place 1.5 tbsp of filling in the center of the circle and fold it into a triangle (or square), firmly sealing the edges. (Traditionally, they are sealed seam-down for Tandoor baking, but seam-up in the oven for better shape retention).
Preheat the oven to 185 °C (365 °F).
Place the Samsa on a baking sheet lined with parchment paper, with the folded seams facing up.
Brush with the whisked egg yolk mixed with water and sprinkle with sesame seeds and/or black cumin.
Bake for 25-30 minutes until the Samsas are golden and the dough is flaky.
Serve the Samsa hot, often with tea or a side of cold sour cream/yogurt.