You need small to medium-sized cubes of paneer for this recipe. Cut and keep aside. Make a paste of onion, green chillies, garlic and ginger. Keep this aside. Whisk yogurt and maida/all-purpose flour together and keep it aside.
Heat oil in a pan and once its hot, add the ground paste and saute for 2 minutes. Then add chopped onion and continue to saute till they turn translucent. Next add the chopped tomatoes along with salt. Cook till the tomatoes turn soft and mushy. Next add the yogurt mixture and immediately stir it all together. Cook it for another 2 minutes. Then add achari masala to the pan followed by turmeric powder, amchur powder, chilly powder and cumin powder. Mix and cook the masala till the oil separates. Add bell peppers and green peas to the pan. Saute for another 2 minutes or till the veggies are cooked. Add little water if you like your gravy little watery. Lastly add the paneer cubes and mix to coat the masala all over the paneer cubes. Garnish with mango pickle masala with oil, kasoori methi and lemon juice and mix well. Serve it hot with any Roti/Naan/Chapati on the side and some sliced onions on the side.