Makes about 450g of sauce

100g old ginger
300g scallions
1 tbs fish sauce
3 tbs sesame oil
150ml peanut or grapeseed oil

1. Scrape the skin off the ginger with a teaspoon, slice into 0.5cm thick slices. Set aside.
2. Slice off and discard the root end of the scallions, discard any wilted leaves. Wash under running water and dry with paper towels. Cut into 4-5cm lengths.
3. Place the ginger in a food processor and pulse (turn the machine on and off rapidly) until it is finely chopped. Do not puree the ginger. Scrape the ginger into a deep pot with a lid.
4. Place the cut up scallions into the food processor and pulse. Stop the machine after about eight pulses. Scrape down the scallions from the side of the bowl, add the fish sauce and sesame oil. Pulse again until the scallions are finely chopped but not pureed. Scrape the mixture into the deep pot. Mix the scallions and ginger well with a spoon.
5. Place the oil in a saucepan set over medium high heat. When you see smoke rising from the oil, turn off the heat. Holding the pot lid in one hand and the saucepan in the other, pour the oil into the pot and clap on the lid immediately.
6. When the hissing and spitting stop, remove the cover, stir the mixture well and have a taste. Add fish sauce or salt if needed.
7. Let cool completely and spoon into a clean glass jar. Store in the fridge and it should last for up to one month. Always use a clean spoon to scoop the sauce out of the jar.

This article was first published in The Sunday Times, 16 August 2015