Get some of the prep work done first by boil a kettle and chopping the potatoes into quarters and cut again into 1cm thick pieces
Peel and grate the ginger (Tip: peel the ginger with a teaspoon scraping the skin across the root) and set aside
Add 1-2 tbsp of olive oil to a large pot with matching lid on a medium high heat. Once the oil is hot, add the potatoes, stir frequentlySlice the spring onions diagonally into 1cm pieces, keeping the whites and greens separated
Meanwhile, in a small bowl, coat the chicken with half of the harissa paste, salt and pepper to taste. Mix well and add to the potato pot, cook for 2 minutes or until brown and seared all over, stirring frequently
Dissolve the stock cube in 500ml (1 pt) of boiling water in a measuring jug. Add the stock to the chick and potato pot. Stir to combine, scraping the bottom of the pot as you bring to the boil
Add the red lentils, half of the whites of the spring onions, remaining harissa paste, ginger and 1 tbsp of yoghurt to the pot
Once boiling, reduce to a rapid simmer and cook with a lid on for 7 minutes, or until the lentils and potatoes are cooked through and most of the water has been absorbed
Meanwhile, combine the remaining yoghurt with the remaining whites of the spring onions. Mix well and season to your taste with salt and pepper
Give the curry a good stir and add 100ml (3.4 fl oz) of boiling water if it is too dry.
Serve up the curry with a dollop of yoghurt and the remaining spring onions.