Bacon, Cheddar and Onion Panetini

Ingredients

• 1 small Onion chopped
• 4 slices bacon
• 2 3/4 cups unbleached all purpose flour
• 2 teaspoons baking powder
• 1 teaspoon kosher salt
• 3 large Eggs
• 4 tablespoons milk
• 2 tablespoons melted butter
• 1 tablespoon olive oil
• 1 tablespoon whole grain mustard
• 4 ounces extra sharp cheddar cheese shredded