In a large bowl, combine the ground beef, grated onion, gram flour, 1/2 teaspoon of garam masala, 1/2 tablespoon of ginger garlic paste, and salt. Mix thoroughly.
Shape the beef mixture into 1-inch round meatballs and set them aside on a plate.
Heat the vegetable oil in a large skillet over medium heat. Fry the beef meatballs until browned on all sides and cooked through, approximately 8 to 10 minutes. Remove the meatballs from the skillet and set aside.
In the same skillet, add the chopped onion and the remaining 1/2 tablespoon of ginger garlic paste. Sauté until the onions are soft and golden brown, about 5 minutes.
Transfer the cooked onions and the cashews to a blender with a splash of water. Blend until a completely smooth paste forms, then return the paste to the skillet over medium heat.
Stir in the tomato puree, coriander powder, turmeric powder, Kashmiri red chili powder, and the remaining 1/2 teaspoon of garam masala. Cook for 5 to 7 minutes, stirring occasionally, until the oil begins to separate from the sauce.
Lower the heat and slowly stir in the heavy cream and dried fenugreek leaves. Simmer gently for 2 minutes to meld the flavors.
Gently fold the cooked beef meatballs into the creamy tomato sauce and simmer for an additional 5 minutes until heated through.
Garnish with freshly chopped cilantro and serve hot alongside warm naan or basmati rice.