Mix all ingredients together in a bowl. The chermoula is now ready to use.
When marinating fish or chicken, you might want to add a little more oil or a tablespoon or two of water to thin the marinade so it’s easier to distribute over the fish.
Leave the chermoula thick if using as a stuffing for fried fish.
Ahead of Time:
Make the Chermoula. Reserve half of the chermoula, and mix the remaining half with the fish. Cover the fish, refrigerate it, and allow it marinate at least two hours or overnight.
Roast the peppers, peel and seed them, and cut them into strips. Or, alternatively, slice the raw pepper into rings.
To Make the Tagine:
Pour the olive oil into a tagine, and distribute the onion slices across the bottom. Criss-cross the celery or carrot sticks in the center to form a bed for the fish.
Mix the potato slices with ras al-hanout, saffron, and arrange the potatoes around the perimeter of the tagine and the dried lime in the middle
Top the potato with the tomato slices, and distribute the reserved chermoula over the vegetables.
Add the fish and its marinade to the center of the tagine, and arrange the strips of pepper on top of the fish in a decorative manner.
Garnish the tagine with the lemon and olives, and sprinkle salt and pepper over all.
Cover the tagine, and cook over low to medium-low heat for about 1 1/2 hours, or until the fish and potatoes test done.
Reduce the sauce if necessary until it is quite thick and mostly oils. (Note: If you feel there is an excessive amount of liquid in the tagine, it’s easiest to ladle the sauce into a pan to reduce it, and then pour the sauce back over the fish before serving.)