Peel the fresh ginger and roughly chop the garlic, serrano pepper, and fresh cilantro.

Pulse the garlic, serrano pepper, fresh ginger, and fresh cilantro in the food processor until finely chopped.

Combine the chopped herb mixture, fish sauce, brown sugar, cornstarch, ground chicken, and salt in the large mixing bowl.

Mix the chicken mixture gently until evenly combined, then roll it into 16 equal meatballs.

Heat the olive oil in a large skillet over medium heat and add the meatballs in a single layer.

Pan-fry the meatballs until golden brown on the first side, then turn them with the spatula.

Add the water to the skillet and cover or partially cover it to steam the meatballs until cooked through.

Remove the lid and continue cooking until the water evaporates and the meatballs are caramelized and golden brown.

Thinly slice the cucumber and shallot, then pick the fresh mint leaves.

Spread 1 tablespoon of mayo over each naan bread.

Fill each naan bread with four chicken meatballs, cucumber, shallot, fresh mint, and fresh cilantro.

Spoon chili crisp over each sandwich and serve immediately.