Take 500 grams of boneless fish (preferably Singhara or Surmai) and cut it into medium-sized pieces. Wash and pat dry the fish pieces.
In a mixing bowl, add 100 grams of besan (gram flour), 1 teaspoon of ajwain (carom seeds), 1 teaspoon of red chili powder, 1/2 teaspoon of turmeric powder, 1 teaspoon of ginger-garlic paste, 1 teaspoon of garam masala, 1 tablespoon of lemon juice, and salt to taste. Mix well.
Add 100 ml of water to the mixture and whisk it to form a smooth, thick batter.
Coat the fish pieces evenly with the batter and let them marinate for 30 minutes.
Heat oil in a deep frying pan or kadai over medium heat. Once the oil is hot, carefully slide the marinated fish pieces into the oil.
Fry the fish pieces until they turn golden brown and crispy on all sides. This should take about 5-7 minutes.
Use a slotted spoon to remove the fried fish pieces from the oil and place them on a paper towel to absorb excess oil.
Serve the Amritsari Fish hot with mint chutney or any dip of your choice.