Make the raspberry vinegar. Halve the raspberries and put them in a small saucepan. Pour the vinegar over, and gently warm over a low heat to a gentle simmer, and leave for a few minutes until the raspberries start to break down. Strain through a sieve, pressing the juice from the raspberries as you do so.
In a deep oven tray, arrange the vegetables, and pour over the liquid. Put in a 180 degree oven for ten minutes, until the liquid is starting to gently steam. Remove the tray from the oven, and lower the temperature to 140 degrees.
Put a wire rack over the broth, and the fish on the rack. The rack should be tall enough not to touch the liquid. Cover the tray in a layer of tinfoil, and put back in the oven, for 20 minutes. The fish should gently steam in this time. Check it by gently pinching it. If it feels fleshy but resistant, it is cooked. allow it to gently cool in its steam bath.
Slice courgettes using a mandolin and arrange over each plate. Break the cold fish down into chunks and arrange around the plate. Garnish with thinly sliced shallots.
Mix 100ml of raspberry vinegar with 100ml of Extra virgin olive oil, and a pinch of salt and a crack of black pepper. Whisk together, and gently fold in 100g of shelled baby peas, and 100g of halved raspberries. Spoon over the fish.