Clean and wash the fish pieces
Pat dry with a paper towel
Marinate with salt, turmeric, chili powder, ginger-garlic paste, and lemon juice
Let it rest for 15 to 30 minutes
Coat lightly with rice flour, cornflour, or gram flour if desired
Heat oil in a pan over medium heat
Place the fish pieces gently into the hot oil
Fry until golden brown on one side
Flip and fry the other side until cooked through
Remove and drain on paper towels
Serve hot with lemon wedges and onions