Mix paneer, yogurt, turmeric and salt. Set aside.
In a frying pan over medium heat, dry roast nigella, coriander seeds, fenugreek seeds, fennel seeds, and black pepper for 1-2 minutes.
Seeds will become darker in color and give off a beautiful aroma.
Crush the roasted seeds using a mortar or rolling pin. Set aside.
Add oil to the same pan, at low-medium heat. Roast red chilies till they turn a darker color.
Remove from pan and break each one into 2-3 pieces.
Increase to medium heat; add asafetida, followed by paneer mixture. Stir fry for 3-4 minutes until most of the moisture has evaporated.
Do not overcook the paneer as it will become dry. The yogurt should coat the paneer nicely so it remains moist. Turn off the heat.
Add all the dry spices and mix well.
Serve warm achari paneer over a bed of spinach leaves.