Place the onions, coriander and parsley in a casserole or saucepan over very low heat. Add the drumsticks and then the black pepper, cayenne pepper, cumin and paprika. Add the chicken stock and drizzle with some olive oil. Cover and gently simmer over low heat for 40 minutes.
Preheat the oven to 200 C / Gas 6. After 40 minutes, transfer the contents of the saucepan into a tagine, mixing well, then add the carrots and the peas. Try not to add too much juice to the tagine to avoid overflowing while cooking in the oven.
Place the tagine with the lid on in the preheated oven and bake for 30 to 40 minutes, until the carrots and peas are soft.
After 30 to 40 minutes, open the tagine and check that everything is cooked to perfection. Arrange the lemon slices on top of the dish, if liked, place the lid back on and bake for 5 to 10 more minutes.
Add salt and pepper to taste and serve hot with fresh bread. Make sure to serve the carrots and peas with the savoury sauce.