Place potatoes and onions in a slow cooker and season with salt and pepper.
Brown the seasoned chicken legs in vegetable oil for 5 minutes per side then place on the vegetables.
Grate the lemon zest, slice a few rounds, and juice the remaining fruit.
Fry the zest, garlic, and ras el hanout in the pan juices for 1 minute.
Stir in the lemon juice and 400ml stock, bring to a boil, and pour over the chicken.
Top with lemon slices, 85g olives, and 15ml olive oil.
Cover and cook on low for six hours until the chicken is tender.
Drizzle with honey, scatter with chopped parsley, and serve with yogurt.