Warm yak meat stew

Ingredients

• 600-800g beef, preferably with fat. I took a piece of the neck, but both the shoulder blade and the back will do;
• 2 leeks;
• 3 garlic cloves;
• 2 liters of water;
• 100 ml soy sauce;
• 200 grams of mushrooms, oyster mushrooms and champignons. Mushrooms, if desired, can be taken more, and they can be varied;
• salt and pepper to taste;
• spaghetti/fettuccine/funchosa at the rate of 100g per person;
• green onions;
• a hard-boiled or half-boiled egg.