The Loblaw's President's Choice Umami paste was wildly overpriced and wasn't all that great.
A product I use for a stealth umami hit to a dish is shrimp paste: http://canada.lkk.com/en/Products/FeaturedProduct/featured_product_20138
I use it in preparations where you may have added a few chopped anchovies. The strong flavour of the raw paste disappears with continued cooking.