Finely dice the white onion, fennel and the mushroom. “Sweat” ( fry in a gentle heat with no colour) the onions for about 2 minutes, add the fennel and finally the mushroom a minute or so later. Cook for a further 2 minutes before adding the cream. Bring to the boil and simmer until the liquid has reduced to a thick consistency. Finish with some chopped dill.
Peel and slice the potatoes into evenly sized chunks. Place in a pot of cold water and simmer until soft and brittle. Strain and mash, it is best to use a ricer but you can do it by hand if you pay attention not to have any lumps left. At this stage add the milk, oil and check the seasoning. You should have a rather soupy consistency, if not just add a little more milk. Now comes the chef's little secret. Pour this into a cream charger (a canister used to whip cream) and add the gas charger. Squeeze the liquid out gently at first holding it downward. You should have a very light mousse
Ensure you have chosen very ripe, but not black Avocados for this. If they need to be ripened further simply place them in a paper bag along with a banana and they should be ripe by morning! Peel and stone them placing them straight into the food blender along with the lemon juice and salt. They should require no other liquid to blend down to a smooth paste but you may have to help them down into the blender from time to time.
To finish the dish cut each fish fillet into 2 even-sized pieces, season and fry on a hot pan with a little olive oil for about 2 minutes on each side, finish with a little squeeze of the lemon and you’re ready to present.
Random is the key, place the hot duxelle around the plate in 5 places, uneven numbers always looks better on a plate. 3 small quenelles (spoon shapes) of avocado around and place the fish on top of the duxelle. Pour out some Espume and spoon around the plate. Use a little bronze fennel or pea shoots to garnish and giving the plate a colourful summer feel. Go back