Combine the shredded chicken, mashed sweet potato, finely chopped ginger, chopped garlic, and chopped green chillies in a large mixing bowl. Add a pinch of white pepper powder and salt to taste. Mix everything thoroughly – the mixture should be cohesive when pressed. Add 4 tablespoons of breadcrumbs to the mixture and mix again. The mixture should be moist but firm enough to shape.

Take a small portion of the mixture (about 1½-2 tablespoons) and roll it between your palms into a smooth ball. Flatten the ball gently between your palms or on a clean surface to create a coin shape – approximately 2 inches in diameter and ¼ to ½ inch thick. The coins should be uniform in thickness for even cooking. Place the shaped coins on a plate or tray. Repeat with the remaining mixture – you should get approximately 12-15 coins depending on size.

Set up a coating station with three shallow bowls or plates. Crack the egg, add 1 tablespoon of water and a pinch of salt in the first bowl and whisk until smooth and well combined – the water helps the egg coat more evenly. Spread out ½ cup of breadcrumbs in the second bowl. Spread the sesame seeds in the third bowl or plate. Have a clean plate ready for the coated coins.

Take one chicken coin and dip it into the whisked egg mixture, ensuring it's completely coated on all sides and let the excess drip off. Next, place the egg-coated coin into the breadcrumbs and press gently, coating all sides evenly. Press the breadcrumbs lightly into the surface to help them adhere. Finally, press the top of the coin into the sesame seeds, or sprinkle sesame seeds over the top. Place the coated coin on the prepared plate and repeat with all remaining coins.

Heat 2 tablespoons of vegetable oil in a large non-stick skillet or frying pan over medium heat. Once the oil is hot, carefully place 4-5 coins in the pan, making sure not to overcrowd. Pan-fry for 3-4 minutes on the first side without moving them, until golden brown and crispy. Using a flat spatula, carefully flip each coin and cook for another 3-4 minutes on the other side until golden and crispy all over. The coins should be heated through and crispy on both sides. Transfer to a plate lined with paper towels to drain excess oil. Repeat with remaining coins, adding more oil if needed.

While still hot, sprinkle additional sesame seeds over the fried coins if desired. Arrange the chicken gold coins on a serving platter and serve immediately while hot and crispy. These are best enjoyed fresh but can be reheated in an oven or air fryer to restore crispiness.