Place beef in the freezer for 15 minutes - this is to help you slice it very fine, so it will cook in the stock.
500 g steak
Put your kettle on to boil. Peel and finely grate ginger. Juice half the lime.
3 cm ginger, 2 lime
Heat a large stock pot or casserole dish on high and add sesame oil, grated ginger and ground cinnamon. Stir until fragrant.
1 tablespoon sesame oil, 1 tablespoon ground cinnamon, 3 cm ginger
Add beef stock, brown sugar, soy, fish sauce and the juice of 1 lime and bring to a boil, then simmer for 15 minutes (reducing). Skim any scum that develops on the top of the broth.
3 L beef stock, 1 tablespoon brown sugar, ¼ cup soy sauce, 2 tablespoon fish sauce, 2 tablespoon lime juice
Pour boiled kettle water over rice noodles and leave for 4 minutes then drain and divide amongst the bowls.
200 g vermicelli rice noodles
Slice remaining lime into wedges. Pick basil leaves, rinse and roughly chop coriander. Finely slice chilli (opt.) and rinse and add bean sprouts to a platter.
½ bunch basil, ⅓ bunch coriander, 1 long red chilli, 125 g bean sprouts
Take the beef out of the freezer and slice it as finely as you can. Distribute amongst the bowls. This will be very rare, so if you’d prefer well cooked meat you can add it to the boiling stock and then ladle into bowls over the noodles.
500 g steak
Taste the stock and add anything that might be missing (salty = soy, sweet = brown sugar, umami = fish sauce, sour = lime juice), then turn up the heat so it’s really bubbling away.
Ladle / pour simmering stock into each bowl. It’s important to return the pot to the heat while doing this, otherwise the stock won’t be hot enough to cook the beef.
To serve, let people add their choice of toppings from the platter.