Bell Light Box
Going to the Bell Light Box and expect to get out around 2-2:30 Sat or Sunday this weekend. I understand Dunn's is very much hit or miss and Canteen has already been tried. What are some good nearby alternative restaurants for a late brunch or lunch?
If you are ok to go a few more blocks, both Marben and Le Select are open either day and both are good.
If Saturday and you still want deli, the Corned Beef House is not bad and is quite close.
Jules Restaurant on Spadina is also a good bet although they are also closed on Sunday.
If you want something directly close, Paese on King is a good choice.
I suggest calling for hours if you want to try Avenue Open Kitchen as I'm not sure what their weekend hours are like - they are not typically open the whole weekend.
Since What-A-Bagel opened across the street, Avenue Open Kitchen has rarely been open on Saturdays, even after their usual summer hours. I live right around the corner and walked by today (Saturday) and they were definitely closed. They have never been open on Sundays.
Not much more options than what has already been suggested for the area. The only other place to think about is Strada 241 if you don't mind a bit of a walk and non-brunch food for brunch.