First make the nuoc cham, by mixing all the ingredients until the sugar has dissolved. Let rest in the fridge whilst you cook the rest.
In a wok or deep pan, heat on medium-high the neutral oil & once hot, fry the egg, carefully splashing the top with the hot oil. Remove from pan once the edges are golden.
In the same oil & wok, add in the garlic, shallots & chillies, stir fry for 30 seconds before adding in the beef & white onions. Stir fry on high until cooked and starting to caramelise, 8-10 minutes.
Next pour in the sauce & cook until glossy, sticky & fully coated.
Turn off the heat, toss in Thai basil & stir until wilted.
Serve hot over the jasmine rice the crispy fried egg and drizzle the nuac cham on top
