I guess I can answer my own question as we ended up going there today for lunch.
Basically it's a scaled-down version of the dinner—I think they do the same on weekdays and have just started weekends too, calling it brunch instead of lunch.
The regular salads and side dishes are available.
They offer seven meats: sirloin, brisket, rump steak, chicken wings, sausage, pork loin, parmesan beef (and chicken hearts when we were there but it wasn't stated on the menu) for $22 or you can chose to have only 1, 2 or 3 with the sides at a lower cost.
Although I missed the ribs and lamb from the dinner selection, this was great!
Gaucho Brazilian BBQ
5920 Macleod Trail S, Calgary, AB T2H 0K2, CA
I've been many times for lunch during the weekday and they usually do have some form of ribs, whether lamb or beef or both, it's easily one of my favourites. Have not managed to get out there for the weekend brunch yet.
Their lunch is a awesome deal but the only problem is if you have to go back to work it sucks as it's food coma time.