Clean and cut 500 grams of fish (preferably boneless) into small pieces. Pat dry with a paper towel.
In a mixing bowl, prepare the marinade by combining 2 tablespoons of ginger-garlic paste, 1 tablespoon of red chili powder, 1/2 tablespoon of turmeric powder, 1 tablespoon of coriander powder, 1/2 tablespoon of garam masala, 1 tablespoon of lemon juice, and salt to taste. Mix well.
Add the fish pieces to the marinade and coat them evenly. Let the fish marinate for at least 30 minutes.
Heat 4 tablespoons of oil in a non-stick pan over medium heat. Once the oil is hot, place the marinated fish pieces in the pan, ensuring they don't overlap.
Cook the fish for 3-4 minutes on each side, or until they turn golden brown and crispy. Flip the fish pieces carefully to avoid breaking them.
Once cooked, transfer the fish pieces to a plate lined with paper towels to absorb any excess oil.
Garnish with chopped coriander leaves and serve hot with lemon wedges and onion rings.