Heat the vegetable oil in a large pot or wok over medium heat. Add the chopped lemongrass and green curry paste. Sauté for 2-3 minutes until fragrant, stirring constantly to avoid burning.

Add the chicken pieces to the pot. Cook for 4-5 minutes, stirring occasionally, until the chicken is lightly browned on all sides.

Pour in the coconut milk and chicken broth. Stir well to combine, scraping up any bits from the bottom of the pot. Bring the mixture to a gentle simmer.

Add the diced eggplant, sliced bell peppers, and kaffir lime leaves. Let it simmer for 10 minutes, or until the vegetables are tender and the chicken is cooked through (internal temperature should reach 165°F).

Stir in the fish sauce, brown sugar, and lime juice. Taste and adjust seasoning with salt, pepper, or more sugar if needed for balance.

Remove from heat and fold in the fresh basil and cilantro. The residual heat will wilt the herbs slightly, preserving their bright flavor.

Serve hot over steamed jasmine rice or your choice of base. Garnish with extra herbs or lime wedges for an added pop.