Heat a pan and dry roast Cumin Seeds, Whole red chillies, Mustard Seeds, Fennel Seeds and Fenugreek Seeds together. After that put it into the blender and make a powder.
Heat 2 tbsp oil in a pan and add chopped onions. Saute until it gets golden.
Now add ginger & garlic paste, turmeric powder, chopped tomatoes, salt, coriander powder and bell pepper. Mix well and cook it for 4-5 mins.
Put tomato and onion mixture into blender and make a coarse paste.
Now heat ½ tbsp oil in another pan and add tomato and onion paste, yogurt, achaari masala and saute it for 2-3 mins. If required, sprinkle some water.
Add diced paneer, sugar and vinegar and cook it for sometime.