Vegetarian Mushroom Manti

Name: Vegetarian Mushroom Manti
Prep time: 1 h 30 min
Cook time: 30 min
Total time: 2 h
Cuisine: European
Ingredients: 2 cups all-purpose flour (plus extra if needed); 1/2 teaspoon salt; 1 egg; ~1 cup water; 1000 g mushrooms (button, shitakki, crimini); 200 g onion; 1 egg white (optional); 1 teaspoon salt; 1/2 teaspoon black pepper; 100 g butter (Melted ); 1 cup yogurt; 2 cloves garlic; Salt; Parsley; 4 cups Vegetable stock