Fillet the fish and keep the bones and heads separate for the flesh.
On the flesh side of the fish, add freshly ground pepper, a little sugar and a little salt. Store in the refrigerator over herb stems and garlic cloves. And you save for the service.
Put the bones with the heads in a dish with two sprigs of parsley. Cover them halfway with cold water and bring to a light boil on a medium stove. You scrape very thoroughly. Strain and keep for later.
Clean and bake the onions in the oven at 220 celsius for 20 minutes. Clean the potatoes and cut them into pieces. Clean the garlic cloves and remove the sprout.
Put everything in the juicer and save for later.
Combine half the fish stock with the vegetable juices in a saucepan, bring to a light boil to cook for a few minutes, for the flavors to bond and for the sauce to thicken slightly, taste and correct for salty, hot and acidic.
Cut thin slices of potato with the mandoline and fry them until they become crispy chips. Kept in a dry environment for service.
Cut the potatoes into small pieces. Clean the garlic cloves and remove the sprout.
Put the olive oil, the garlic cloves in a wide pan and cook on a medium heat until they become confit and you flavor the olive oil. Remove the garlic and set aside for serving. Add the potatoes and start cooking them on a medium stove, stirring regularly so that they too become confit with the aromatic olive oil. Add a little of the remaining fish stock and cook until the potatoes soften well and absorb the stock. Pass them through a sieve to make a puree, add lemon zest, taste and correct if necessary. Keep warm for serving.
Beat the taramo paste with lemon juice and an ice cube or cold water in the bimmer. Add olive oil and homogenize as if you were making an emulsion. Test and correct if necessary.
Put the fish in a pan on top of the herbs, pour olive oil and put in the oven at 130 celsius with 10% humidity for about 8 minutes or until the heart reaches 42 celsius. As soon as it is ready, burn the herbs and the edges of the fish with the flame so that it is very lightly smoked.
Reheat the mash and the sauce separately.
Make a circle with the tarama on the plate. Place the puree in the middle. Top with the fillet and finally the chips. Drizzle with Paxini bianco sauce.