In a 2L pressure cooker, add 15 large gooseberries, 1/2C water, 1/4 tsp turmeric & 1tsp salt. Cook on high for 3 whistles. Allow pressure to settle. Remove the seeds.
Whisk 2.5C thick sour yogurt with 2tsp mustard powder, 2 1/2 tsp chilli powder, 1/2 tsp hing, 1 1/2 tsp salt & 2 tbsp vinegar. Mix with gooseberries. Refrigerate. Let soak for 2-3 days.