Roux

Ingredients

• 240 g (2 cups) bread flour
• 1/2 teaspoon fine sea salt
• 1 teaspoon instant yeast
• 15 g (1 Tablespoon) sugar
• 1 large egg, room temperature
• 100 g milk, room temperature
• 30 g (2 Tablespoons) unsalted butter, room temperature
• 4 Tablespoons unsalted butter, room temperature
• 1/2 teaspoon Coleman's dry mustard powder
• 1 teaspoon Marmite
• 100 g shredded sharp cheddar
• 2 Tablespoons chopped fresh chives