If you've been to the St. Lawrence market, I'm sure you've been to Kozlik's before. It's a tiny little shop in the middle of the main floor that always has a bunch of people surrounding a hotplate. What do they sell? The best mustards you've ever had and the most variety of mustards that you've never even knew existed.
Now first of all, I actually think the best thing about Kozlik's isn't their mustard, but the fact that they cook pea meal bacon for you to taste all their delicious kinds of mustards. AMAZING! I could probably spend a good hour here sampling and deciding on which mustard I like the best... Oh, for you veggies, they also have pretzels to try out all the different types of mustard.
It's a really hard task to actually find out which one you love the most, they're just too many that are good. Personally I like the German one the most, but depending on the food and what floats your boat, you may find another winner in their cornucopia of mustards.
This is always a stop for me in the St. Lawrence Market. And for some reason I always come out with a jar of mustard. Gah! Damn you effective sampling!