Sprinkle ribs with 1 teaspoon salt and 1/4 teaspoon pepper. In a large skillet, brown ribs in 3 tablespoons oil in batches. Place ribs on a rack in shallow roasting pan.
Bake, uncovered, at 350° for 20 minutes. Turn ribs; bake 20 minutes longer. Pat dry.
Place potatoes in a large saucepan and cover with water. Bring to a boil. Reduce heat; cover and cook for 10-15 minutes or until tender.
Meanwhile, in a large saucepan, saute onion and garlic in remaining oil until tender. Stir in the flour, parsley, and remaining salt and pepper until blended. Gradually stir in milk. Bring to a boil; cook and stir for 2 minutes or until thickened.
Drain potatoes; place in a greased 13-in. x 9-in. baking dish. Top with sauce and ribs.
Cover and bake at 350° for 15 minutes. Uncover; sprinkle with paprika. Bake 5-10 minutes longer or until ribs are tender and potatoes are heated through.