Make the meatballs: In a large bowl, combine the ground pork mince, egg, breadcrumbs, coriander, spring onions, garlic, ginger, salt, and black pepper. Mix gently until just combined, being careful not to overwork the mixture as this can make the meatballs dense. Roll into evenly sized balls, approximately the size of a golf ball, and set aside on a plate.
Brown the meatballs: Heat the oil in a large pan over medium-high heat. Add the meatballs in a single layer, working in batches if needed to avoid crowding the pan. Cook for 10-12 minutes, turning occasionally, until browned on all sides and cooked through. Remove from the pan and set aside, leaving about a tablespoon of the cooking oil in the pan.
Build the sauce: Reduce the heat to medium. Add the sliced red onion and garlic to the pan with a pinch of black pepper and cook for 2 minutes until softened. Add the sliced red bell pepper and cook for a further 2-3 minutes. Stir in the red curry paste and cook for 2 minutes until fragrant. Pour in the coconut milk and stir well to combine. Add the lime or lemon juice and let the sauce simmer for 5-8 minutes until slightly thickened. Taste and adjust seasoning with salt and pepper.
Finish the dish: Return the browned meatballs to the pan and nestle them into the sauce. Simmer gently for a further 5 minutes to allow the meatballs to absorb the flavours of the sauce.
Serve: Spoon the meatballs and sauce over fluffy cooked rice and top generously with fresh coriander, sliced spring onions, and lemon or lime wedges on the side.
