Bulgarian cuisine has incorporated Turkish and Greek influences and is characterized by a careful and refined processing of vegetables and the quality of their ingredients.
Musaka is prepared with minced meat, half beef, half pork, the vegetables are mostly peppers, but also sauerkraut or leek are often used for this traditional casserole.
Fry the minced meat in oil over medium heat, stirring occasionally. Cut the peppers and tomatoes into pieces of up to two centimeters. Add the bell pepper pieces to the fried minced meat, mix thoroughly, season with paprika powder, salt and parsley (or other herbs) and steam a little more.
Cut the peeled potatoes into very thin slices.
Cover the bottom of a gratin dish with the potato slices. Put the minced meat and bell pepper mixture on the potatoes and spread the tomato pieces evenly on top. Layer a second layer of potato slices on top of this filling. Spread a mug of ketchup diluted in water evenly over the casserole – the potatoes need this liquid to soften.
Put the gratin dish into the oven at 190 °C. In half an hour the potatoes will be cooked, which is time enough to make the sauce.
In a saucepan, heat the butter and mix in the flour with a whisk. Add a quarter of a liter of water and a quarter of a liter of milk and stir briskly until you have a smooth mixture.