1/4 cup brown mustard seeds
1/4 cup yellow mustard seeds
1/2 cup white wine
1 teaspoon kosher salt
Place mustard seeds in a medium-size bowl. Stir in 1/2 cup cold water and the wine. Cover and let stand overnight.
Purée mustard with salt until you reach the desired consistency. Transfer to an airtight container and refrigerate for 24 hours before using.
YIELD One and 1/2 cups.
NOTE: After puréeing, flavor the mustard by adding sweet vinegar, black pepper, chopped garlic, herbs, honey, horseradish or chopped shallot.