Heat a medium pot over medium-high heat. Heat oil and ghee and add the whole spices.
Add onion and sauté until golden, about 10 minutes. Add the garlic and ginger and continue to sauté until the raw smell disappears, about 30 seconds.
Add beef and stir-fry for about 5 minutes or until it changes color.
Lower the heat and add the powdered spices and salt and sauté for about 20 seconds.
Carefully pour this beef mixture into your Crockpot or slow cooker.
Add the water and stir to mix. Cook on low for 8-10 hours (preferable) or high for 6-7 hours, or until the beef is fall-apart tender. Cooking times will vary depending on your meat and slow cooker.
Toward the end of your cooking time, remove your whole spices and take out a cup of the liquid of the Nihari into a bowl. Let it cool a little by adding an ice cube to it.
Place the atta in another bowl. Bit by bit, add the Nihari liquid to the atta to form a smooth slurry. Slowly add this slurry back into the crockpot while stirring to prevent clumps. Let it cook for another 30-45 minutes. Serve hot with the garnishing and naan or sheermal.