On the 5th floor of the Shanghai Art Museum across the street from the JW Marriott, Kathleen's 5 is a lovely space with good western cuisine for reasonable price. Went for a lunch on pleasant Friday afternoon, and sat outside on their covered patio.
They have a two course or three course prix fixe menu for lunch. I had the Caesar salad and split main -- sea bass and swordfish (I think I liked sea bass with potatoes better). Their site of potatoes was crispy fried and salty (which I guess can make even cardboard taste good...) and it came with a good aioli.
325 Nanjing Xi Lu, Shanghai 200003