Step 1

Cook potatoes in boiling water in saucepan 25 min. or just until tender; drain. Cool. Meanwhile, cook bacon as directed on package.

Step 2

Heat oven to 350°F. Crumble bacon; reserve 1/4 cup. Cut potatoes into 1/4-inch-thick slices. Whisk flour and milk in large bowl until blended. Stir in sour cream. Add potatoes, remaining bacon and 2 Tbsp. chives; stir to evenly coat potatoes.

Step 3

Pour into 2-qt. casserole sprayed with cooking spray; top with cheese.

Step 4

Bake 30 to 35 min. or until heated through. Sprinkle with remaining chives and reserved bacon.