Place the ground chicken, the white part of the scallions, garlic, water chestnuts, and egg in a large bowl. Add 2 tablespoons of the fish sauce, 1 tablespoon of the curry paste, 1 tablespoon of the palm sugar, toasted rice powder, cornstarch, and fresh ground pepper to the bowl. With a clean hand, toss to integrate until a cohesive mixture forms.
Wet your hands with water and form the chicken mixture into 16 evenly sized meatballs. Use a heaping tablespoon as a guide. Set the meatballs aside
Place the eggplant pieces, cut-side-up, on a piece of paper towel. Sprinkle with the salt and set aside.
Pour 2 tablespoons of the canola oil into a large deep skillet. Place over medium heat and heat until shimmering. Reduce the heat to medium-low and add the chicken meatballs. Don't crowd the pan. You may have to work in batches. Brown the meatballs on both sides and transfer to a plate. Set aside.
Add the wine to the skillet and deglaze the pan. Add the eggplant to the pan, cut-side-down, and cook until caramelized and tender. Transfer the eggplant to a plate and set aside.
Pour the remaining canola oil into the pan and heat until shimmering. Add the remaining curry paste (or more if you like it spicy) and saute until bubbling and fragrant. Pour in the coconut milk and bring up to a boil. Boil for 2-3 minutes until the oil from coconut milk separates and pools on the surface. Reduce the heat to low.
Fill the coconut milk can with water and give it a swish. Add the water to the skillet along with the kaffir limes leaves, bamboo shoots, meatballs, eggplant, shimeji mushrooms, and the remaining palm sugar. Simmer for 15 minutes or until the meatballs are cooked through.
While the curry is simmering, bring a large pot of water to a boil. Add the noodles and cook for 5 minutes or until tender. Drain and rinse the noodles with water. Set aside.
Take the curry off of the heat and taste. Depending on how salty your curry paste is you may or may not have to add the remaining tbsp of the fish sauce.
Divide the noodles amongst four bowls. Spoon the curry over the noodles, adding 3-4 meatballs to each bowl. Garnish with Thai basil leaves, lime wedges and the sliced green sections of the scallions. Serve immediately with a cold Thai beer.