Creamy au Gratin Potatoes

Malzemeler

• Malzemeler
• 3 yemek kaşığı all-purpose flour
• 3 yemek kaşığı butter
• 1 medium onion, sliced into rings
• 800 g medium russet potato, thinly sliced
• 2 bardak milk
• 0.5 çay kaşığı salt
• 10 g salt and ground black pepper
• 1.5 bardak shredded Cheddar cheese