1Heat vegetable oil in a large pot or Dutch oven over medium-high heat. Add pork belly cubes and sear on all sides until golden brown and crispy, about 8-10 minutes. Remove pork and set aside, leaving rendered fat in the pot.

2Reduce heat to medium. Add red onion, garlic, and ginger to the pot and sauté for 3-4 minutes until softened and fragrant. Stir in the red curry paste and cook for another 2 minutes, stirring constantly until aromatic.

3Pour in half of the coconut milk and the chicken broth (or water). Bring to a simmer, then return the seared pork belly to the pot. Reduce heat to low, cover, and gently simmer for 45-60 minutes, or until the pork is very tender.

4Add the remaining coconut milk, fish sauce, palm sugar, and lychees to the pot. Stir gently and continue to simmer uncovered for another 10-15 minutes, allowing the sauce to thicken slightly and flavors to meld.

5Stir in the fresh lime juice and Thai basil leaves. If using, add the sliced bird's eye chilies. Cook for just 1-2 minutes until the basil wilts. Taste and adjust seasoning as needed, adding more fish sauce, sugar, or lime juice to balance flavors.

6Serve hot, garnished with extra basil leaves or chilies if desired, traditionally with jasmine rice.