At Gastronomia Peck in Milan, one of the greatest food stores on the planet, a signature pairing on their beautiful cold platters is spiny lobster or scampi with porcini mushrooms. This recipe takes from that elegant combination, making a perfect accompaniment for baked, grilled, or poached fish, like salmon, seabass, and halibut. Try it instead of plain mayonnaise in shrimp or lobster salad, or as a great alternative to louis dressing with cocktail shrimp and crab. And for land-based occasions, have it in sandwiches with cold roasted meats or chicken salad.
1Blend the oils and set aside. Bring 1/2 cup water to a boil in a small saucepan and add the mushrooms. Remove from the heat and set aside to steep for 10 minutes to reconstitute.
2Place the egg, yolk, mustard, lemon juice, salt, and pepper in a food processor. Lift the mushrooms out of the water and gently squeeze out as much water as possible over the sink. Set aside the mushroom water left in the pan. Roughly chop the mushrooms and add to the food processor. Purée the mixture and, with the machine running, slowly add the blended oils in a thin, steady stream to make an emulsion. Spoon 2 tablespoons of the lukewarm mushroom water off the top and add in a steady stream while the machine is running. The mayonnaise can be used immediately or covered with plastic wrap and refrigerated for up to a week.
Note: This recipe contains raw eggs. People with health problems, the elderly, or those who are pregnant should avoid consuming food with uncooked eggs, which, in rare cases, carry the potential for salmonella infections.