I read about Completo a few weeks ago and had to head over to Kensington Market to find it. It's at 214 Augusta, down a little alley and you can easily walk by without noticing it.
When you walk down the alley you enter a little backyard with some beautiful graffiti and plastic table & chairs.
I had the sirloin steak strip sammy and their fries. The steak isn't a whole piece of meat, it's strips that are marinated then cooked on their flat top grill. It's served on a nice soft bun and topped with mashed avocado, chopped tomatoes and some spicy sauce. This was an amazing sandwich. The avocado worked really well in this, personally I would've liked this more spicy.
The fries were shoestring fries and just as delicious as the sandwich. Perfectly salted and crispy.
I would definitely recommend this little 'blink-and-you-miss-it' sandwich joint.