Instructions

1. Chop the spring onions finely and dry them at 57 °C for 10 hours. Spring onion is mostly water and the green tops collapse to almost nothing, so start with more than looks sensible.
2. If you are adding the chicken, dry it separately at 71 °C rather than alongside the onions. Poultry needs that higher setting to be safe and the onions would scorch at it.
3. Pack the dried onion, chicken and rice noodles into one large zip bag, the powdered egg and coriander into a small bag of their own, and the oil, soy, sugar, lime powder and peanuts into a third. Keeping them apart matters: the egg powder cakes if it meets the sugar, and the peanuts go soft against anything damp.
4. At camp, pour boiling water into the noodle bag until everything is well under the surface and press the air out before sealing it. Anything floating above the water line stays hard.
5. Leave it ten minutes while you mix the egg powder with a few tablespoons of water and scramble it in a little of the oil. It is done when it holds together in soft curds rather than staying wet.
6. Drain the noodles and check them: they should be soft and separate, not sticky. If they are still firm, cover them with more hot water rather than trying to fry them soft.
7. Heat the rest of the oil and stir the soy, sugar and lime powder into it until the sugar has melted into a syrup. That is what will coat the noodles; a sauce with undissolved sugar just sits in the bottom of the pot.
8. Fold the noodles and the egg through the sauce off the heat, then scatter the peanuts and coriander over the top. The peanuts go on last so they still have some crunch when you eat it.
9. Kept as three sealed bags in a cool dark cupboard the kit holds six months, or two if you included the chicken. The peanuts and the oil are what fail first, so pack those two fresh before a trip rather than leaving a made-up kit for a year.