Melt butter and oil in a large skillet over medium heat until the foam disappears from the butter, and stir in the steak cubes and onion. Cook and stir until the meat and onion are browned, about 10 minutes. While beef is cooking, mix together corn flour, seasonings, salt, ginger garlic paste,and black pepper in a bowl. Sprinkle the flour mixture over the browned meat, and stir to coat.

In a large soup pot, pour in the beef broth and water, and stir in the tumeric and bay leaf. Stir in beef mixture, and bring to a boil. Reduce heat to medium-low, cover the pot, and simmer, stirring occasionally, until meat is tender, about 45 minutes..

Mix in the potatoes, carrots, and tomato paste; bring the soup back to a simmer, and cook uncovered, stirring occasionally, until the vegetables are tender and the soup is thick, 15 to 20 minutes. Remove bay leaf and serve hot.