Cheesy Ham and Potato Casserole

Bahan-bahan (8 porsi)

• 3 tablespoons butter
• 3 ½ tablespoons all-purpose flour
• 1 small onion (diced)
• ¾ cup milk
• 1 cup reduced sodium chicken broth
• 1 teaspoon salt (or more to taste)
• ½ teaspoon black pepper
• 1 cup shredded sharp cheddar cheese
• 3 pounds potatoes (peeled and diced)
• 2 cups diced ham
• 2 cups frozen peas (defrosted)
• 1 ½ cup shredded sharp cheddar cheese (or to taste)