Heat oven to 350 degrees F. Coat a 2-quart casserole dish lightly with no-stick cooking spray.
Cut potatoes into quarters. Place in large saucepan. Cover potatoes with water. Add 2 teaspoons salt. Bring to a boil. Cook about 15 to 20 minutes or just until potatoes are fork-tender. Drain. Place in prepared dish.
Melt shortening in medium saucepan over medium heat. Add flour. Whisk until well combined. Gradually whisk in milk. Whisk in 1 teaspoon salt, pepper and paprika. Bring to a boil, whisking constantly. Remove from heat. Stir in sour cream, 3 tablespoons chives and 1 cup cheese. Pour evenly over potatoes. Top with remaining cheese and crumbled bacon.
BAKE 20 to 25 minutes or until bubbly and golden brown. Let stand 10 minutes before serving. Garnish with remaining chives.