Massaman and Panang curry may look similar as pastes, but their flavors differ, as do the ingredients that are usually put in their curry dishes. Panang is a red curry to start with, but it has a richness from the use of coconut milk and an unusual Thai ingredient — peanuts. The Spruce Eats explains it as being both rich and sweet. Because it’s made with dried chilies, it has a slight heat.
Dating back to 1890, according to Asia Highlights, Panang is made with lemongrass, galangal, coriander, garlic, cumin, and shrimp paste. The coconut milk and peanuts make it thicker than most curries. What makes Panang’s rich and developed flavor a little brighter is the addition of citrusy and fragrant kaffir lime leaf, as described by The Kitchn. Instead of being ground into the paste, lime leaves are tossed into the curry dish to wilt slightly. What you get is a flavor-loaded bite whose punch eventually mellows to the sweetness of the coconut milk, explains Great British Chefs.