Mustard Creole Sauce:
1 yellow onion, peeled and sliced
1 red bell pepper, seeded and chopped
1 ½ teaspoons Creole seasoning
1 tablespoon olive oil
1/2 cup white wine
2 cups heavy cream (1 pint)
1 ½ cups chicken stock
1 ½ tablespoon whole grain mustard
1 teaspoon kosher salt
1 teaspoon black pepper
Sauté the onion, red pepper, olive oil and Creole seasoning over medium-low heat until the vegetables have softened and the onions appear translucent. Add the white wine and cook over medium heat until the liquid has reduced by half, about five to seven minutes.
Stir in the cream, chicken stock and whole grain mustard and continue to cook over medium heat for ten to fifteen minutes, stirring occasionally. Once the vegetables are completely cooked and soft to the bite, puree the mixture with a handheld immersion blender, food processor or liquid blender, until smooth and velvety in texture, and thick enough to coat the back of a spoon. If it seems too thin, continue to cook over medium heat for ten more minutes.
Taste the sauce and add salt and pepper to taste, starting with a teaspoon of each, stirring to incorporate. Remove the sauce from stove and serve immediately or refrigerate in an airtight container for up to one week.