Bring a large pan of water to a boil with salt. While waiting for it to boil, scrub and clean the potatoes. Then halve any big ones. Boil the potatoes for 15 minutes until cooked through.Push a small, sharp knife through the largest piece. If it glides through, they're done. Don't overcook the potatoes.While the potatoes are cooking, we’ll make the sambal.
When the potatoes are done, drain them and leave to steam dry for a couple of minutes.
Ginger and Spring Onion Sambal
Make this while the potatoes are cooking or earlier. It keeps in the fridge for a week. The video below doesn't include the sambal, as that's already covered here.Scrape the skin off the ginger and chop up roughly.Chop up the spring onions and chillies roughly.
Pestle and Mortar: Start with pounding a few ginger pieces for about 10 seconds. Add ⅓ of the spring onions and all the chillies and pound until they're coarsely pounded.The initial ginger acts as a base to pound the thin spring onions on.
You can also do this in a food chopper. In which case, place everything in and pulse to get a coarse grind. Or semi fine, whichever you prefer.
Add a few more ginger pieces and another third of the spring onions and pound.Finish this with the rest of the ginger and spring onions and pound until you're happy with how big or small the pieces are. I like a coarse grind.
Cook the Sambal Briefly
Heat up the oil in a small frying pan on medium heat to simmering. I like to use 6 Tbsp of oil, but you can use just 4, if you prefer.Place a wooden utensil in your oil, and if you see tiny bubbles hugging it, your oil is hot enough.
Turn the heat to medium-low and tip the pounded aromatics in and cook for 2 minutes.
Take it off the heat and stir in the soy sauce and taste it. If it needs more salt, you can either add more soy sauce or salt. The more soy sauce you use the less vibrant green your ginger and spring onion sambal will be.Keep the rest of the sambal in the fridge for up to a week.
Bring Everything Together
Mix the sambal and mayonnaise together in a small bowl.
Add to the drained potatoes and very gently mix it all together, ensuring that the potatoes are fully covered.
Finish off with some freshly ground black pepper and optional chopped spring onions or fresh coriander leaves.