Crabmeat Cakes with Mustard Sauce

INGREDIENTS

• 2 tablespoons unsalted butter
• 1 large egg yolk
• 3 tablespoons whole-grain mustard
• 1 tablespoon all-purpose flour
• Kosher salt and freshly ground pepper
• 2 teaspoons yellow mustard seeds
• 1 tablespoon olive oil, for frying
• 1 cup milk
• 1 stalk celery, finely chopped
• 1 teaspoon paprika
• 1/2 cup low-sodium chicken broth
• 1/4 cup finely chopped dill pickles
• 1 tablespoon unsalted butter, for frying
• 1/2 cup mayonnaise
• 2 teaspoons curry powder
• 1 pound lump crabmeat, picked over for shells
• 6 slices white bread, crusts removed