Combine oyster sauce, fish sauce, soy sauce, sugar, and water in a small bowl. Stir until the sugar dissolves. Set aside.

Roughly chop the garlic cloves so you get small uneven pieces. Slice the chilies into thin rounds. Thinly slice the shallots.

Heat a wok or large skillet over high heat until smoking. Add the vegetable oil and swirl to coat.

Add garlic, chilies, and shallots. Stir constantly for 30 to 45 seconds until fragrant and the garlic just starts to turn golden at the edges.

Add the ground beef in an even layer. Press it flat against the pan and leave undisturbed for 60 to 90 seconds until the bottom develops a brown, caramelized crust.

Break up the beef with a spatula and continue cooking over high heat, stirring occasionally, for 3 to 4 minutes until most of the pink is gone and you see crispy browned bits throughout.

Pour in the sauce mixture. Stir to coat the beef evenly and cook for 1 minute until the sauce thickens slightly and glazes the meat.

Remove the wok from the heat. Add the fresh basil leaves and fold them in quickly - residual heat will wilt them in about 20 to 30 seconds.

Spoon the beef over steamed jasmine rice. Top each plate with a fried egg if using, and serve immediately while the basil fragrance is still strong.