In a skillet, toast the coriander, mustard, and cumin seeds, along with black peppercorns, over low heat until fragrant—about 5 minutes. Allow them to cool before grinding in a food processor.

Add cilantro root, shrimp paste, salt, lime leaves, lime zest, chiles, garlic, shallots, lemongrass, galangal, and coconut milk. Blend until smooth and creamy.

In a food processor, blend the tilapia fillets with salt until smooth. Gradually add cold water to reach a paste consistency. Mix in cornstarch, sugar, and white pepper until fully combined. Roll into small balls and refrigerate for about 30 minutes.

Bring a pot of salted water to a boil. Carefully add the fish balls and cook until they float and are tender, approximately 5-7 minutes. Remove them from the pot and set aside to cool.

In a saucepan, heat the coconut cream over medium heat until the oil separates, about 4 minutes. Add the prepared curry paste and cook, stirring constantly, for another 4 minutes. Gradually stir in coconut milk along with some water, bringing the mixture to a gentle boil. Simmer with the fish balls and eggplant until the eggplant is tender, roughly 20 minutes.

Stir in fish sauce, palm sugar, extra lime leaves, and chiles. Remove from heat and gently fold in the basil leaves. Serve warm, ideally with hard-boiled eggs and jasmine rice.