Steeles Deli is one of my favourite breakfast places in Thornhill. I think it's better than Kiva's, and equivalent to Centre Street Deli (and cheaper). Although it can get quite busy on weekend mornings, the food is delicious. The place is smaller than Centre St Deli and Kiva's, but like most breakfast places, there's a quick turnover.
One of the most unique food items at this place is the corned beef hash. This is a difficult item to find in Thornhill, but this deli has it, and it's delicious. The deli specializes in other sandwiches and has a great breakfast menu too.
I would recommend this place to anyone. It's great, and I will keep on coming back.