Preheat oven to 350 degrees F. For sauce: In a medium saucepan, cook onion in a small amount of boiling water over medium heat for 3 to 5 minutes or until tender. Drain; return to pan. In a screw-top jar, combine milk, flour, and pepper; cover and shake until well mixed. Add milk mixture to saucepan. Cook and stir over medium heat until thickened and bubbly. Stir in rosemary.

Meanwhile, in a 2-quart microwave-safe baking dish, combine potatoes, turnip, and the 1/4 cup water. Cover with vented plastic wrap. Microwave on 100% power (high) about 8 minutes or just until vegetables are tender. Carefully drain in a colander.

In the same 2-quart baking dish, layer half of the ham, half of the potato mixture, and half of the sauce. Repeat layers. Sprinkle with paprika. Bake, uncovered, about 30 minutes or until heated through. Let stand for 10 minutes before serving. Makes 6 servings.