Heat a tbsp of oil in a large pan over medium-high heat. Cook the beef mince for 5-7 minutes or until browned, stirring occasionally.
Add onion and garlic to the pan and continue cooking for 2-3 minutes until the onion is softened.
Add grated carrot and sliced cabbage to the pan and stir-fry for 2-3 minutes until the vegetables are just tender.
Mix soy sauce, oyster sauce, brown sugar, and black pepper in the pan, and stir until well combined. Cook for another 1-2 minutes until heated through.
Remove the pan from heat and allow the mixture to cool to room temperature.
To make the lumpia, lay a spring roll wrapper flat with one corner facing towards you. Spread a thin line of beef mixture (about a tablespoon) onto the wrapper, leaving a 2cm gap from the edges.
Fold the corner nearest to you over the filling, then fold in the sides. Roll the wrapper up tightly, brushing the remaining corner with beaten egg to seal.
Repeat the process with the remaining spring roll wrappers and filling.
Heat enough oil in a deep frying pan or wok to deep fry the lumpia until golden brown for about 3-4 minutes. Drain on kitchen paper.
Serve the beef lumpia hot with sweet chili sauce or your preferred dipping sauce.
