Heat 1 tbsp butter in a pan over medium heat.
Add the bay leaf, black cardamom, cinnamon stick, green cardamom, cloves, chopped onion, chopped garlic, and ginger in to the pan. Sauté onion until translucent.
Now add the chopped tomatoes, green chili, Kashmiri chili powder, cashew nuts, and salt to the pan and mix everything together. Add 1/2 cup water and cover the pan with a lid. Let it cook for 20-25 minutes over a medium-low flame or until the tomatoes are soft and mushy.
Turn off the heat and let the tomato mixture cool down.
REMOVE bay leaf, black cardamom, and cinnamon stick from the pan. We need to remove these 3 ingredients because if you grind these spices with tomato mixture it will change the color of the gravy to darker and the taste will be different.
Once cooled, puree the tomato mixture in a blender until smooth. If it is finely blended there is no need to strain it. However if something isn’t fine with your mixer or you see some chunk then you may want to strain it.