To make the sea trout, preheat the oven to 55C/45C Fan. Pour the oil into a roasting tin and preheat for 10 minutes.
Season the trout with salt and pepper and place in the roasting tin, then confit in the oven for 30 minutes, turning half way.
Meanwhile, to make the sauce, place the cauliflower, milk, cream and salt in a large saucepan. Cover with a lid or cartouche and cook for 10–15 minutes. Place the mixture in a blender or food processor and blend until smooth.
To make the cauliflower, heat a frying pan over medium-high heat, add the oil and butter and once frothing add the garlic and cauliflower and fry until crispy. Remove from the oil with a slotted spoon and transfer to a plate with kitchen paper.
In a large bowl mix the pan fried cauliflower, capers, parsley, chives and lemon together.
Serve the sauce on a plate topped with the trout, pile on the cauliflower mixture and finish with the roe and dill.
