O melhor é usar a palavra em português, entre aspas, explicando, numa Nota do Tradutor, do que se trata, algo como:

"A system of serving food, specially grilled meats, where the client is entitled to eat any and all of the plates that are offered by waiters who circulate by the restaurant and cut pieces directly to your plate, according to your prefference."

Veja estes exemplos e referências:

Rodizio - Bedfordview, restaurant in Bedfordview, Northern Region ...
... as you like from a wide selection of chourico, chicken, beef, pork and lamb cuts all slow grilled on our ... and mixed spices to give each cut of meat its own ...
www.eating-out.co.za/member_menu.asp?MemberID=1576

sundaytimes.co.za :: Home of the Sunday Times :: South Africa's ...
... and the menu explained to us. We settled for the Rodizio special,
which basically consists of all the grilled meat you can eat. ...
www.suntimes.co.za/lifestyle/eating/ reviews/r-rodiziovictory.asp

Utah Restaurant Guide, Featured Restaurant, Rodizio Grill, Salt ...
... at your table from the salad bar, your "Meat Servers" begin to appear offering you
a variety of selection from beef tenderloin to grilled pineapple. ...
www.utahrestaurantguide.com/rodiziogrill/

Rodizio Rico London - Restaurant Review and Information
... Very interesting, specially for meat lovers ... chaps walking up and saying 'a little
more beef/lamb/chicken ... Brazilian myself, I took my girlfriend to Rodizio Rico a ...
www.london-eating.co.uk/2877.htm

--------------------------------------------------
Note added at 2003-10-06 02:41:47 (GMT)
--------------------------------------------------

Typo: preference (só um \"f\")