In a bowl, mix ginger-garlic paste, red chili powder, turmeric powder, coriander powder, cumin powder, lemon juice, and salt. Adjust the spice levels according to your preference.
Apply the prepared marinade generously on both sides of the fish slices. Make sure the fish is coated well with the marinade. Allow it to marinate for at least 30 minutes to 1 hour in the refrigerator.
Take a frying pan or a shallow frying dish and heat oil on medium flame. You'll need enough oil to shallow fry the fish slices.
If you prefer a crispy texture, dust the marinated fish slices with rice flour before frying. This step is optional but adds crispiness to the fish fry.
Once the oil is hot, carefully place the marinated fish slices into the pan. Fry them on medium heat until they turn golden brown and crispy on both sides. Be gentle while flipping the fish slices to avoid breaking them.
Once fried, remove the fish from the oil and place them on a plate lined with paper towels. This will help absorb excess oil.
Arrange the fried fish on a serving plate. Garnish with lemon wedges and fresh coriander leaves for added flavor and presentation.
Mangalorean-style fish fry is best enjoyed hot with some sliced onions and a wedge of lemon on the side. It pairs well with steamed rice, chapatis, or as a standalone appetizer.