Pho broth is made from beef, bones, vegetables and spices cooked slowly to release and combine their flavours. Rinse beef and pork bones in cold water then quickly blanche them in boiling water to get rid of that coppery, raw taste. Using these bones, make your broth with beef, white turnips, ginger, a mix of grilled red onions and regular onions, and herbs like star anise, cinnamon sticks, and bay leaves. Slowly simmer the broth for at least four hours before serving.

Fish sauce does not go bad or change flavour. Good fish sauce is more pungent as it comes from the first liquid extraction of fermented small fish, usually anchovies. It has a sweeter aftertaste and is transparent. Look for labels with 40° on them as opposed to25° or lower, as better grades have higher numbers. The best fish sauce comes from the Vietnamese island of Phu Quoc.

In Vietnam, fish sauce is as important to cooking as salt is to other world cuisines. The Vietnamese use it in everything. Personally, I like to mix equal parts of fish sauce and white vinegar with three times the water. Then I add sugar, lime, chopped red onions, garlic and chili to taste.

Vietnamese cuisine uses many fresh herbs, and some of the more widely-used herbs include basil, cilantro, mint, red perilla, lemongrass, dill and Vietnamese coriander known as rau răm.

Brush your rice paper with a little water and sandwich each sheet between layers of cold, damp towels just before wrapping. The filling should be pre-cooked, cooled and completely dry. Shape some of your filling into a long rectangle on one side of the rice paper, leaving just enough room to cover over it. On the far edge, dab an egg yolk and flour mix made from80 per cent yolk and 20 per cent flour. Fold the two flanking edges over the filling, then the near edge over the filling, and continue rolling. Seal the spring roll with the egg yolk. It should not be too tight or too loose, and the ends should not bulge out. Cover with a damp towel until deep-frying for10-12 minutes in 180°C oil.

It is harder to wrap a cold spring roll as they require more ingredients that are harder to pack together, and are usually made with thinner sheets of rice paper. You have to wrap a cold spring roll tighter than a fried one without losing its shape or tearing it. Also, use larger sheets of rice paper for cold spring rolls.

Use a non-stick wok because vermicelli easily sticks, and add your vermicelli after stir-frying your other ingredients. Begin by sautéing chopped red onions, then stir-fry crab meat and strips of vegetables seasoned with fish sauce, pepper and chicken powder. Pre-soak the vermicelli in cold water for ten minutes, drain it and then add it to your stir-fry last along with bean sprouts.