Cut off the fish head off directly behind the gills, if desired.
Now rinse he fish of, inside and out, in cool water then cut fish into halves, lengthwise.
Pat fillets dry with a paper towel.
Sprinkle lime juice and lemon juice over the fish.
Put salt and ginger-garlic paste on the fish.
In a small bowl, mix together the rice flour, plain flour, red chili, coriander powder, cumin powder, all spice powder, turmeric powder, carom seeds (ajwain) with 1 tablespoon water and make a smooth paste.
Dab this paste onto fish and refrigerate for 6 hours or preferably overnight.
Remove from the fridge and strain excess water.
Heat a large griddle (tawa) or cast-iron pan over high heat.
Remove from the fridge and strain excess water.
Heat a large griddle over medium heat.
When the pan is hot, add the mustard oil ( you can use any cooking oil).
Put the fish on the griddle, skin side down (if applicable), laying them down away from your body.
If fish fillets have skin, press down gently with a spatula for about 20 seconds to prevent curling.
Lower heat to medium and let sizzle until fish is crispy, golden and caramelized around edges, about 5-7 minutes.
Carefully flip fillets and add some mustard oil to the griddle.
Tilt the griddle slightly to let the mustard oil pool at one end.
Use a spoon to baste the fish with the mustard oil.
Continue basting until golden all over and cooked through, 2-3 minutes more, depending on the thickness of your fish.
Take it out in a serving platter when crispy and golden brown from outside and cooked from inside.
Sprinkle chaat masala and lemon juice over it.
Garnish with Lemon slices.
Your Restaurant Style Tawa Fish is ready to eat.
ENJOY!!