First take the achari or pickling spices in a pan - fennel seeds, cumin seeds, mustard seeds, nigella seeds and fenugreek seeds.
Heat the pan and on a low flame roast the spices till they are fragrant. Don't brown them.
Once cooled, add the spices in a small dry grinder or spice grinder and grind to a semi fine powder.
Remove the achari masala powder and keep aside in a bowl.
Making masala base
In the same grinder, add 10 to 12 cashews.
Grind to a fine powder. If oil releases while grinding then its fine.
In a bowl, take fresh whole milk curd/yogurt and whisk it till smooth. Use fresh curd and not sour curd.
Heat mustard oil or sunflower oil or ghee in a pan.
On a low flame, add 2 dry red chilies and a generous pinch of asafoetida. Saute for some seconds till the red chilies change color.
Then add ginger-green chili paste. Stir and saute till the raw aroma of ginger goes away.
Then add the chopped tomatoes and stir.
Add turmeric powder, red chili powder, coriander powder and cumin powder (optional).
Again stir very well and saute the tomatoes till the tomatoes soften completely and become pulpy. You should also see oil releasing from the sides.
Now add the cashew powder. If using store brough cashew powder, then add 2 tablespoons cashew powder. Do check the shelf life of store brought cashew powder before adding.
On a low to medium flame, stir and saute the mixture for 2 minutes after adding cashew powder.
Reserve 1 teaspoon of the ground achari masala and add the rest. Stir very well.
Add 1 tablespoon besan. We are adding besan so that the curd does not curdle. You can swap besan (gram flour) with chickpea flour.
Stir the besan very well and incorporate it into the rest of the masala.
Making paneer achari gravy
Keep the flame on a low and add the beaten curd.
As soon as you add the curd, begin to stir the mixture quickly and fast. Stirring quickly, incorporate the curd well into the rest of the masala.
Add salt as per taste.
Simmer for 2 to 3 minutes on a low flame.
Add the paneer cubes. 200 or 250 grams paneer chopped in cubes.
Cook the paneer cubes for about 20 to 30 seconds and switch off the heat. Don't cook for more time as then paneer cubes may lose their softness and will become hard.
Then add light cream or low fat cream. Also add crushed kasuri methi to the gravy. Gently stir very well.
Switch off the flame and add chopped coriander leaves and chopped mint leave. Stir gently again.
While serving sprinkle the reserved achari masala from top and garnish with a coriander or mint sprig. Serve achari paneer masala with tandoori roti, chapati, rumali roti, plain paratha or naan.
This recipe can't be scaled easily. Try to follow the recipe as it is without making any changes in the ingredient proportions. Since this is a complexly flavored gravy, any changes may off-balance the taste.
Use fresh curd or yogurt. The curd should not be sour as then the gravy will become very sour.
For the achari masala use spices that are fresh and have not gone rancid.
I would suggest making this dish when you plan to serve it hot and fresh. Don't make this dish ahead as on refrigeration the flavors will change and while reheating the paneer cubes will become dense.