Shape the beef mixture into meatballs.
Heat the olive oil in a wide pot over medium heat. Add the onion and cook until golden, about 8 minutes.
Stir in paprika, baharat, black pepper, and tomato purée, cooking for 1 minute.
Add the meatballs to the pot, searing for 1 minute per side. Add the mushrooms, boiling water, and salt. Bring to a boil and cook over high heat for 10 minutes.
Lower the heat to a simmer, cover, and cook for 1 hour. Remove the lid and cook for another 7 minutes to reduce the liquid. Serve hot.