Cheesy Au Gratin Potatoes Recipe

• 10 potatoes , peeled and sliced
• 1 medium onion , sliced
• 1/2 cup butter
• 1/4 cup flour
• 4 cups milk
• 1/2 lb bacon , cooked and crumbled
• 1/2 teaspoon basil
• 1/4 teaspoon dry mustard
• 1/2 teaspoon salt
• 1 teaspoon thyme
• 1/2 cup cheddar cheese , shredded
• 1/2 cup Velveeta cheese , cubed

Directions