good eats near sheraton centre
You can also go to Mercatto on Bay (Bay & Adelaide) which is under 5 minute walk from Sheraton). I work right next to Sheraton so I end up going there often. Their pizza and pasta are pretty decent. During lunch time, either go early or late (avoid going between 12:30-1) because it gets packed. I usually go at 11:55 and get a seat for two sans probleme.
For brunch, try Eggspectations - it is on Yonge St, north of Queen. Not far at all for you. Also at that location is Baton Rouge, which has great ribs.
You can get an EXCELLENT take out Burrito at Burrito Boyz - just walk West on Adelaide, it is on the north side of the street.
The best wings in Toronto are at Duff's, which is on College Street, near Bathurst. There are a bunch of great bars in that area, you can't go wrong heading up that way.
Order in? No don't do that. Go to Terroni on Adelaide, a short walk for you on the other side of Yonge, certainly a contender for best Neopolitan-style pizza in Toronto. Great pastas and apps too. Very well-priced.
Brunch I'm not sure, I'm more of a breakfast then lunch kind of guy mostly.