Savoury Muffins With Feta Cheese, Onion and Rosemary

INGREDIENTS

• 275 g plain flour
• 1 tablespoon baking powder
• 1 teaspoon salt
• 1 egg
• 225 ml milk
• 1 tablespoon butter
• 1 medium onion, finely chopped
• 100 g feta cheese, chopped into small cubes
• 1 tablespoon chopped fresh rosemary
• fresh ground black pepper
• 1 egg, lightly beaten