Chard-Grilled sturgeon with baked potato broth and grapefruit oil
Finely grate half a grapefruit onto table salt and mix with chopped rosemary. Place the sturgeon in this salt mixture for 10 minutes, then remove, wash and dry with kitchen paper.
Place the fillets skin side down in a frying pan with a little olive oil and fry on one side only until the skin is crisp. Just before serving, grill over charcoal.
Baked potato broth
Carefully wash the potatoes then cut off peelings half a centimeter thick. Bake the potato peelings in the oven at 180ºC / 356ºF for 40 minutes. Simmer in 1/2 l / 2 1/6 cups of water for 30 minutes, then decant. Cut the leeks into pieces and cook for three minutes in the potato broth. Then brown on the charcoal grill.
Grate the rind of the remaining half a grapefruit and set aside. Cut up the grapefruit flesh and infuse in the potato and leek broth for 2 minutes. Strain and decant.
Heat the sunflower oil to 40ºC / 104ºF and add the grated grapefruit rind. Cover, leave for 10 minutes, then strain.
Place the pieces of char-grilled sturgeon and leek on a soup plate with a few drops of extra virgin olive oil. Add pieces of the chive stalk and curls, then add the Riofrío caviar. Pour a little potato broth over the dish, and finish with a few drops of grapefruit oil.
"The delicate, elegant flavor of the sturgeon, rich in collagen and marbled with fat, is served with a light vegetable broth that accompanies but provides no added flavor. The grapefruit oil just refreshes the broth, helping to lighten the sturgeon fat, and the charcoal smoke brings out all the aromas."