Wipe out skillet and heat remaining 2 Tbsp. oil (still over medium-high). Add curry paste, palm sugar, 2 tsp. fish sauce, and 3 whole lime leaves. Cook, stirring often, until paste darkens slightly, about 1 minute. Add pork and cook, stirring and breaking up, until in small pieces, about 2 minutes (pork doesn’t need to be fully cooked at this point). Pour coconut milk into skillet and reduce heat to medium. Simmer, stirring occasionally, until pork is cooked through and curry thickens slightly, about 5 minutes.