means Cooking food, especially meat, by exposing it to dry heat in an oven or over a fire — or, figuratively, subjecting someone to a barrage of mocking criticism.

from From the Old French 'rostir,' to roast or burn, which English borrowed in the medieval period. The French itself likely came from a Germanic source — a cousin of the Old High German 'rosten,' to roast — suggesting the word crossed back and forth between cooking cultures. The sense of 'roasting' a person with insults is much younger, an extension of the heat-and-discomfort idea, with the comedic 'roast' as a formal event of affectionate mockery being a 20th-century American invention.