EnlargeCredit: Christopher Hirsheimer
YIELDS 1 CUP
2 large egg yolks 2 tbsp. lemon juice 1 tsp. dry mustard ½ tsp. salt 1 cup olive oil Freshly ground black pepper
1. Combine egg yolks, lemon juice, mustard, salt, and 2 tbsp. water in the top of a double boiler. Cook, whisking constantly, over gently simmering water over medium-low heat until mixture begins to thicken (and reaches a temperature of 160°), 2–3 minutes.
2. Transfer yolk mixture to a bowl (or food processor), then, while whisking vigorously (or mixing), slowly drizzle in oil to make an emulsified sauce. Adjust seasonings with salt and pepper. (Store in refrigerator for up to 1 week.)