Slice the Onions: Start by peeling and slicing 400 g of onions thinly.

Cook the Beef: In a large pan, melt 100-120 g of butter over medium heat. Add the sliced onions and sauté until they turn soft and translucent.

Add the Beef: Cut the beef into medium-sized chunks and add them to the pan with the onions. Pour in 50 ml of water and stir. Cover the pan and cook the beef on medium heat for 60 minutes. Stir occasionally to prevent sticking.

Season the Beef: After 60 minutes, add the minced garlic, 1½ to 2 tsp of salt, and black pepper to taste. Stir well and continue cooking the beef, covered, for another 90-120 minutes over low heat, until the meat becomes tender and soft.

Heat the Pan: While the beef is cooking, heat a separate pan over medium-high heat. Add 1-2 tbsp of olive oil and a small amount of butter.

Fry the Mushrooms and Onion: Add the chopped onion and sauté until soft and golden brown. Then, add the sliced mushrooms and cook, stirring frequently, until the mushrooms turn golden brown. This should take about 8-10 minutes.

Add Garlic and Seasonings: Add 2-3 cloves of minced garlic, salt, black pepper, and a tablespoon of sour cream. Stir to combine and cook for an additional 2 minutes.

Finish the Mushrooms: Stir in the chopped parsley and cilantro, then remove the mushroom mixture from heat and set aside.

Mix in the Mushrooms: Once the beef is tender, add the mushroom mixture into the beef. Stir well to combine all the flavors.

Add Mozzarella: Sprinkle 100 g of shredded mozzarella cheese on top of the beef and mushroom mixture. Cover the pan and allow the cheese to melt over medium-low heat for about 5 minutes.

Heat the Cream and Water: In a small saucepan, combine 80 ml of cream (or milk) and 80 ml of water. Heat gently over medium heat.

Thicken the Sauce: In a small bowl, mix 2-3 tsp of flour with a bit of water to create a smooth slurry. Gradually stir this slurry into the warm cream mixture to thicken the sauce.

Season the Sauce: Add salt, black pepper, and a pinch of nutmeg to taste. Simmer for 2-3 minutes until the sauce thickens to your desired consistency.

Combine with Beef: Pour the creamy sauce over the beef and mushroom mixture and stir to combine. Let the entire dish simmer for another 10-12 minutes on low heat.

Serve: Once everything is well-cooked and the flavors have melded together, remove from heat. Garnish with additional parsley or cilantro, if desired.

Store Leftovers: If you have leftovers, store them in a covered bowl in the refrigerator. Reheat gently over low heat or in the microwave.