1. Heat the oil in a medium size saucepan, add the garlic, potatoes, tomatoes and spice mix.
2. Mix all the ingredients well and cover with water.
3. Place a lid on the pan and gently bring to the boil, skimming all froth from the surface as the water begins to bubble.
4. After about 10 minutes, check to see if the potatoes are cooked by gently inserting a knife into the largest potato cube.
5. When cooked, add the harissa, preserved lemons and parsley and gently shake the pan to swirl in the remaining ingredients.
(Using a spoon will squash the cooked potatoes).
6. Continue to cook without the lid on a low heat until the potatoes are completely cooked and the sauce has reduced
by a quarter.
(You could lift out the potatoes whilst the sauce reduces, returning them to the pan after the sauce has thickened).
7. Serve whilst hot.
