Grind spinach, coriander leaves, mint leaves, fenugreek leaves, green chillies and yogurt in a blender. Add garam masala powder, red chilli powder, turmeric powder and salt. Marinate mutton in this masala for one hour, preferably in a refrigerator.
Heat oil in a pan and add onion. Sauté till translucent, add ginger and garlic. Sauté till golden brown in colour. Add the marinated mutton and sauté for five minutes.
Add one cup of water, cover and cook for thirty to thirty five minutes or till mutton gets cooked and the oil leaves the masala. Serve hot with paranthas.