I haven't worked the EZE-SCL sector in a while, so I can't remember if the meal is a hot or cold one. There's a tray service of some kind, but nothing elaborate. I'll look it up and post when I get a chance--probably over the next day or so.

The flight across the Andes is often bumpy, so eating is sometimes not particularly pleasant. When skies are clear, though, (and only in daylight, obviously--I'm not sure offhand what time the flight leaves EZE nowadays) the scenery is spectacular. If you end up on a non-refurbished plane, definitely go for 2 seats on the window side.