In a small bowl, mix chopped chilies, garlic, fish sauce, and lime juice. Set aside.
Heat a wok or large skillet over high heat and add vegetable oil.
Once hot, add the ground beef, spreading it out in the pan.
Sear the beef without stirring until the underside is browned.
Stir and continue cooking until the beef releases its liquid. Keep stirring until the liquid evaporates and the beef starts to sizzle in its own fat.
Once sizzling, allow the beef to cook undisturbed for 15-20 seconds to further brown. Repeat this process 1-2 more times.
Reduce heat to medium, push the beef to one side, and add the garlic and chilies. Sauté for 30 seconds until fragrant.
Stir the garlic and chilies into the beef.
Add sugar, black pepper, and beef broth, mixing well. If it looks too dry, add more broth.
Turn off the heat and stir in fresh basil just until wilted. Adjust seasoning with more sugar or fish sauce, if needed.