Ingredients
1 tablespoon plus 1 teaspoon Dijon mustard
1 large egg yolk
2 teaspoons fresh lemon juice
Coarse salt and freshly ground pepper
1/2 cup olive oil
2 tablespoons grainy mustard
2 teaspoons prepared horseradish
1 tablespoon water, plus more if needed
Preparation
Whisk together Dijon mustard,egg yolk, lemon juice, 1/4 teaspoonsalt, and 1/8 teaspoonpepper in a bowl. Pour inoil in a slow, steady stream,whisking constantly untilemulsified and thick. Whiskin grainy mustard, horseradish,and water. (Thin withmore water if too thick.)
