Whisk besan into yogurt until smooth. On medium-low, add yogurt in a thin stream while whisking. Simmer gently 4 to 5 minutes without a hard boil.
Add salt, optional sugar, and water as needed. Simmer 3 to 4 minutes until thick and glossy.
Finish
Fold in paneer gently. Simmer 2 to 3 minutes until heated through. Garnish with cilantro and serve hot.
Notes
Curd split? Off heat, whisk in 1 tbsp besan mixed with 2 tbsp cold yogurt, then return to low simmer.Less oil: Use 2 tbsp total oil for a lighter weeknight version.No onion-garlic: Skip onion; use extra tomato and ginger; add asafoetida in the tempering for Jain-style meals.Refrigerate leftovers up to 2 days. Reheat gently with a splash of water.Bitter gravy often means too much fenugreek or burnt spices. Measure fenugreek carefully.