I heard Ruby Wax speak on a panel yesterday and she mentioned comedians "doing a roast". She had to explain to the (mostly British) audience what that meant.
It is in the OED with the definition: "Now chiefly N. Amer.: a mock serious ceremony at which a guest of honour is subjected to good-humoured ridicule or banter". Ruby Wax seemed to imply it was crueller than that. In British English we have the word "roasting", but this isn't particularly good-humoured - it means a scolding.
Nowadays we would say "rule the roost" (= be dominant) but this is a later (late 18th century) version, and a folk-etymological variation, according to the OED, of the earlier phrase "rule the roast", which the Dictionary says was in common use from 1500 onwards. The original meaning of "roost" was "roof framework", so I suppose that 'rule the roost' sounded fairly logical ie rule the house.
The OED has other idiomatic phrases based on "roast", which usually have something to do with value or wealth (pay for the roast, run away with the roast, promise of roast, share of the roast and others). The phrase "cold roast" appears in the "cold" entry and means (or meant - the OED says it is obsolete) "something of little account".