Wash the slices of fish and marinate with salt, turmeric powder and ginger garlic paste.
Refrigerate for 3o to 45 minutes.
In the meantime, to prepare the masala paste, heat ½ tsp oil in a pan.
Add red chillies, coriander seeds, cumin seeds, methi seeds and peppercorns.
Roast the spices till they turn aromatic and crisp.
Allow the roasted spices to cool down.
Transfer to a mixer jar.
Add chopped onion, garlic, tamarind, salt and ¼ cup of water.
Blend to a fine paste. Keep this aside.
Next, heat 2 tbsp oil in a pan.
Add the masala paste.
Saute on low flame.
Add curry leaves and mix well.
Saute till the masala is cooked well and starts leaving the sides of the pan.
This may take around 10 to 12 minutes.
Now, add the marinated fish slices.
Coat the fish slices with masala paste.
Cook the fish on both sides.
Garnish with chopped coriander leaves.
Serve Surmai Tawa masala with onion rings and lemon wedges.