We are a family or 2-4 (I have my 2 kids every other week)
I don't know if Montreal is considered LCOL or HCOL (I live in the city of Montreal itself), but I typically spend $700-800 monthly on food items. Going to the Jean Talon market or buying directly from a farm would be less expensive, but I have to factor in the time consideration (I work FT, am a PT student, plus have girls who are in competitive level sports).
I scope the weekly flyers either online or that are delivered to the house, and I usually plan my meals accordingly. If chicken is on special we usually buy quite a lot, cook them up, then freeze them. We do the same with most other types of meat.
I try to avoid packaged foods as much as possible.
In terms of fruits and veggies, I try to buy them fresh from Jean Talon market as often as I can (once a month or so), and I usually prefer buying 'locally' than 'organic' that can be bought in a supermarket. Other than that, I buy from the supermarket, and try as much as I can to buy locally or Canadian.
I'd like to shave $100-$200 off of my grocery expenses, but in Quebec it is a challenge. Especially with the high cost of milk/dairy products (mind you, not as high as in the territories or farther north).
I do live close to several ethnic shops (Pakistani, Algerian, Mexican, Vietnamese, Italian) which sell items cheaper than in the supermarket. For example, at the Italian bakery down the street (which sells ready-made whole wheat pizza dough for 2 large pizzas for $2.50) they sell 400g of the REAL parmesan cheese still in its original state for $8. In the grocery store it's $13-17.