Scrub the new potatoes and dice them into chunks around 1/2 cm big. Peel and finely slice the red onion.
Warm 1 tbsp olive oil in a hevay based frying pan. Add the potatoes. Season with salt and pepper. Fry for 15-20 mins over a medium heat, stirring often, till the potatoes are golden and starting to look crisp.
Grate the zest from the lime. Juice it. Finely slice the chilli, flicking out any seeds if you prefer less heat. Peel and finely grate the ginger. Combine them all in a bowl. Add the beef. Turn to mix. Leave to marinate for 10 mins.
Shred the lettuce. Toss the lettuce with 2 tsp olive oil and some salt and pepper. Put to one side for later.
Add the onion to the potatoes. Stir and fry for 5 mins till the onions are soft. Take the pan off the heat.
Add 1/2 tbsp oil to a separate frying pan. Add the beef to the pan (keep the marinade). Stir fry for 4-5 mins till the beef is browned and cooked through. Tip in the marinade. Cook and stir for 1 min to warm everything through.
Pop the potatoes back on the heat. Pile the beef into the pan. Cook and stir for 1-2 mins to warm everything through.
Serve the hash in bowls topped with spoonfuls of the yogurt and a few of the coriander leaves. Serve with the lettuce on the side.