Marinate the Chicken simply with salt & pepper
Heat some oil and add in the grated Onion
Add the green Chillies
Add in the Ginger & Garlic paste
Add the Onion seeds
Add in all the powdered spices and dried Fenugreek leaves
Mix this well together
Add the Tomato puree & Yogurt
Add the Casher paste
Add the reserved Onion juice and 1 cup of Water
Cook this for about 10 mins
Allow it to reduce down
Taste for Salt and add it to taste
Add the rest of the Water
Garnish with chopped Coriander leaves