Combine the mustard, tarragon, lemon juice, garlic, paprika, salt, and pepper in a large bowl and mix well.
½ cup whole grain mustard, 2 tablespoons chopped fresh tarragon, 1 tablespoon lemon juice, 1 clove garlic, ½ teaspoon paprika, ½ teaspoon pepper, ¼ teaspoon kosher salt