Crush walnuts coarsely. Heat ghee in a non stick pan, add crushed walnuts and saute till fragrant.
Add khoya and mix and continue to saute. Add milk powder and mix well and continue to saute.
Add milk and mix. Add green cardamom powder and sugar and mix well and cook on medium heat till the mixture thickens to halwa consistency. Serve warm garnished with walnut kernels.