Heat oil in a pot and add sliced onions. Fry until golden brown.
Add whole garam masala and ginger-garlic paste. Sauté for a minute.
Add beef mince and cook for 2 minutes on medium flame.
Add blended tomatoes, turmeric, red chilli powder, red chilli flakes, coriander powder, salt, and cumin powder. Mix well.
Add potato cubes, 1 cup water, and pressure cook for 3-4 minutes.
In another pan, lightly fry capsicum and onion cubes on low flame for 4 minutes.
Add them to the mince and potato mixture. Cover and cook for 5 minutes on medium flame.
Garnish with garam masala, green chillies, coriander leaves, and julienned ginger.
Serve hot with roti or naan.