Heat oil or butter in a pan.
Add chopped onion and sauté until golden.
Add ginger-garlic paste and sauté for 1 minute.
Add tomato puree and cook till oil separates.
Add turmeric, chili powder, coriander powder, and salt.
Stir in cashew paste and cook for 2–3 minutes.
Add ½ cup water to adjust consistency. Simmer for 5 minutes.
Add cream and garam masala. Stir well.