This cutesy cafe that's snuggled deep in the 400 acres that make up High Park was bustling when I visited it yesterday. Might I add that it was 1pm on a Tuesday?
Grenadier Cafe is located at the heart of High Park at the junction of West Road, Colborne Lodge Road and Deer Pen Road (where the small year-round zoo is). It's also at the intersection where you'd head off to watch "A Dream In High Park" at the amphitheatre in the summer months.
There's a huge (fake) maple tree that spans the entire indoor part of the cafe, which makes you kinda feel like you're still outside. And unlike the former "cafeteria" feel, the place has been renovated to now include a full menu, including all-day breakfast and sandwiches. Once you've ordered and paid, you take a number to your table and a server brings your food to you. My dad and I ordered two breakfast specials (I got 3 poached eggs with grilled vegetables and homefries and he got a breakfast sandwich with homefries) and with drinks the total came to about $15. Suuuper cheap.
Gotta agree with Luke that the best part about the cafe is the outdoor patio, which is gargantuan and wraps around most of the restaurant. Because it backs onto West & Colborne Lodge, there's a lot of traffic and it's a great spot to people-watch. There's also an outdoor ice cream hut in the patio area where you can order scoops and Drumsticks, Oreo Ice Cream Sandwiches and the like.