From George Graham here.

• ¼ cup Creole mustard or spicy brown mustard
• 1 tablespoon Dijon mustard
• 2 tablespoons sugar
• ¼ cup cane vinegar
• 1 tablespoon heavy cream
• 1 tablespoon Greek yogurt
• 1 cup olive oil
• Kosher salt and freshly ground black pepper

Add the mustards, sugar, vinegar, cream, and yogurt. Whisk while slowly drizzling in the olive oil.