Combine soy sauce, lime, and beef in a bowl, Mix well and let it stay for at least 30 minutes.
Heat oil in a pan and start to pan fry the beef sirloin in medium heat for 1 to 2 minutes per side.
Pour-in the remaining marinade and the beef broth. Add garlic powder and ground black pepper. Stir. Cover and simmer for 20 to 35 minutes. Add more beef broth if necessary.
Remove the cover and add the onion and scallion. Cook for 3 minutes.