First, let's begin with preparing the skin. For this, you must mix the flour, salt, and oil. Knead it with water slowly until smooth. Once the dough is formed, make a ball and soak it in oil until it sinks for around an hour. While the dough is soaking, we can start preparing the vinegar sauce.
For the vinegar sauce, grab a small pot and add water, palm sugar, garlic, and chilli. Let the mixture boil for a minute before adding salt and vinegar. Correct the taste, turn off the stove, strain the sauce, and add chopped chilli and onions. Set it aside.
Now, let's move on to the filling. Heat some oil and fry onions and garlic until they're sweet-smelling. Add minced beef and stir well until it changes colour. Then add salt, white pepper, chicken powder, and sauté everything until cooked. Finally, add the curry powder and remove from heat. Let it cool.
In a separate bowl, beat some eggs, add the stir-fried minced beef and chopped scallions, and mix everything. Set this mixture aside.
After an hour, take the dough out and put it on a Teflon. Spread and flatten the skin until it's thin enough to cover the Teflon surface. Heat the Teflon until the skin mixture is slightly lifted and the edges dry. Add the filling, spreading it evenly over the martabak skin. Fold the martabak like an envelope using a wooden spoon.
Put cooking oil on the edges of the martabak and fry it on all sides until it's cooked and golden yellow. Then, transfer the martabak to a plate cut into small pieces and serve it with your special sauce. Enjoy!