In a large bowl, combine the chicken, garlic, fish sauce, sugar, and black pepper. Marinate for at least 30 minutes.
Heat the oil in a large pot or deep skillet over medium heat.
Add the sugar and cook until it melts and turns a deep amber color.
Immediately add the marinated chicken and stir to coat each piece in the caramel.
Cook for 5–7 minutes, or until the chicken is lightly browned.
Push the chicken to one side of the pot. Add the shallot and ginger, then sauté until fragrant.
Pour in the water and bring to a gentle simmer.
Cover and cook for 20 minutes.
Stir in the fish sauce and dark soy sauce.
Add the hard-boiled eggs and Thai chili peppers.
Simmer uncovered for an additional 10 minutes, turning the eggs halfway through so they absorb the sauce evenly.
Serve hot with steamed white rice and spoon the rich caramel sauce over the chicken and eggs.