For preparing Cashew Chicken Curry, blend together onions, ginger, cumin seeds and garlic in a mixer grinder. Keep aside.
Keep the cashew nuts immersed in water for 10 minutes.
Blend it to paste in a mixer grinder.
Heat oil in a pan.
Add mustard seeds and when they splutter, add onions (chopped length-wise) and saute, till onion turns brown.
Add the blended onion paste.
Stir well and add chilly powder, coriander powder and chopped tomatoes.
Add turmeric powder, salt and add washed chicken pieces.
Add enough water and allow it to boil.
When the chicken pieces are cooked, add lemon juice and stir well.
Add blended cashews.
When mixture starts boiling again, turn off the flame.
Garnish with coriander leaves.