scalloped potatoes with three cheeses

Ingredients For scalloped potatoes with three cheeses

• 3/4 c

  extra sharp shredded cheddar cheese
• 3/4 c

  crumbled danish blue cheese
• 1/3 c

  freshly grated parmesan cheese
• 4 lb

  russet potatoes, cut in 1/4 in slices
• 1 1/2 tsp

  salt
• 1/2 tsp

  pepper
• 1/4 c

  finely chopped onion
• 3 Tbsp

  flour
• 4 Tbsp

  butter
• 3 c

  whole milk