1. Peel the peppers with the help of a Pyrex® peeler for thin skins. remove the seeds and the pith, then cut them into slices. Chop the onions and the garlic. Peel the tomatoes and cut them into four.
2. Fry the onions in the casserole dish with 3 tablespoons of olive oil. Add the peppers, the tomatoes, and the garlic. Salt and pepper. Cover and leave to simmer for 30 minutes.
3. During this time, chop the shallot and cut up the coriander. Place the fish on the baking paper. Sprinkle on the shallot, the coriander and the cumin. Salt and pepper. Close up the papillotte and place it in the steam basket.
4. Once the 30 minutes cooking time is up you can add 1 tablespoon of olive oil to the peppers if you like.
5. Place the steam basket on the casserole dish, cover and cook for 20 minutes. The shakshouka should be soft, even stewed. Just before serving, remove from the heat and add 2 egg yolks, stiring vigorously. Serve as a starter with slices of toasted brown bread or as an accompaniment to the fish.