Finely chop the stems and the bakoula leaves a little less finely.
Steam for about 20 minutes, either in the basket of the couscoussier, or in a steamer basket over a large pan of water (the volume of the leaves will decrease very quickly).
Prepare the seasoning
Finely chop the parsley and coriander.
Crush the garlic cloves.
Separate the flesh of the preserved lemons from the skin. Cut the peel into small pieces.
Heat the olive oil in a frying pan, add the spices and herbs (except garlic) and leave in the hot oil for a few minutes (5 maximum).
Finishing the bakoula
Once the mallow leaves are soft, return the pan to the heat and add the garlic, mallow leaves, lemon juice and preserved lemon flesh.
Mix and sauté for 10 minutes.
Serve in a large dish, adding the olives and pieces of preserved lemon peel as decoration.
Notes
It's difficult to give exact quantities, as khobiza is sold in bunches of varying, non-standardised size!Let's say that for a starter or side dish for 4 people, you need around 200 - 250 grams of cooked leaves, and that they reduce in size like spinach, but a little less. Spinach loses a lot of weight: 1 kg of raw spinach yields around 300 g cooked.For this salad, as we're using the stems, which lose a lot less, I think you need to start with around 600 grams raw. But if you experiment with other values, let me know in the comments!