In Britain, what foods do you traditionally or typically have with a roast?

A lot depends on the meat and the season.

I try to include a root vegetable (carrots) and a green (cabbage, broccoli, beans, peas)

Roast lamb, carrots, peas, new potatoes and mint sauce.

Roast chicken, roast potatoes, carrots, broccoli.

Roast beef, roast potatoes, carrots, cabbage, Yorkshire pudding, mustard.

Roast pork, roast potatoes, carrots, peas apple sauce.

There's usually onions, garlic, herbs included.

They vary from household to household. In this house we are vegans and vegetarians, so our roast is actually a kind of nut-luncheon. With it we have carrots, cabbage, broccoli, roasted aubergine, roast parsnips, mint/cranberry sauce/applesauce, gravy, and of course roast potatoes and sometimes mash too. My favourite part is the Yorshire puddings.

Glazed carrots

New potatoes with peas

Yorkshire pudding

Mashed potatoes

Roasted potatoes

Sage and onion stuffing

Favorite part of the roast, the end pieces that are a bit crusty and highly seasoned; the cook's nibble in the kitchen.