1Cook the spelt in a large saucepan of boiling salted water for 30 minutes. Drain it and rinse it under a stream of cold water. Pour into a bowl and add a tablespoon of olive oil. Keep cool.
2Roughly cut the cauliflower. Keep 4 tops for garnishing. Place the cauliflower in a saucepan, cover with milk, add a pinch of salt and the bay leaf. Cook, simmering until the cauliflower is tender. Drain but keep the cooking liquid. Remove the bay leaf. Puree the cauliflower in a blender by adding a little cooking liquid to obtain a smooth purée. Add the juice of half a lemon and salt, set aside.
3Heat the grill. Lightly oil your fillets on the skin side, then salt to taste. Place them on the hot side of the grill (smoking). Once they are almost done cooking, turn the fillets over for 5 seconds and remove them.
4Chop the chervil
5In a saucepan, mix the cauliflower purée with the spelt; warm over low heat. At the last moment add the chervil. Season with salt and lemon juice.
6Spread the spelt on the plates. Top with the fillet. Add the zest of the different citrus fruits, the trout eggs and the arugula, dressed with olive oil. Lastly, grate the tops of remaining raw cauliflower and sprinkle onto the plates.