- 1/3 cup hazelnuts (about 1 ounce)
- 1/4 cup extra-virgin olive oil
- 1 shallot, finely chopped
- 1 tablespoon plus 1 teaspoon sherry vinegar
- 2 teaspoons fresh lemon juice
- Coarse salt
- 1/4 cup hazelnut oil or light vegetable oil, such as canola
- Freshly ground pepper
Preheat oven to 375 degrees. Spread hazelnuts in a single layer on a rimmed baking sheet. Toast in oven until skins split and flesh turns deep golden brown, 10 to 12 minutes. While still hot, rub hazelnuts in a clean kitchen towel to remove skins (some will remain). Coarsely chop.
Heat the hazelnuts, olive oil, and shallot in a small skillet over medium heat, stirring, until shallot softens, about 2 minutes. Let cool slightly.
Stir together vinegar, lemon juice, and 3/4 teaspoon salt in a medium bowl. Whisking constantly, pour in hazelnut oil and then hazelnut mixture in a slow, steady stream; whisk until emulsified. Season with salt and pepper.