1 tablespoon lemon juice
3/4 cup canola or vegetable oil
1 teaspoon truffle oil (or more to taste)
1. In a small food processor, combine the egg yolks, salt, lemon juice and truffle pieces (if using).
2. With the food processor on, slowly add the canola oil in a thin stream into the eggs. Finish by adding the truffle oil. Adjust the seasoning to taste. Cool and reserve.
1/2 cup tomato paste
2 tablespoons sugar
1/4 cup truffle vinegar
2 teaspoons kosher salt
In a small saucepan over medium heat, bring 1 cup of water, the tomato paste, sugar, vinegar and salt to a simmer. Cook, stirring frequently, until a ketchup-like consistency has been reached, about 10 minutes. Adjust the seasoning to taste. Cool and reserve.
Burgers and assembly
4 (8-ounce) Kobe-style hamburger patties (the restaurant uses Snake River Farms)
1/4 pound truffle cheese
4 brioche buns
2 tablespoons truffle butter