Ingredient selection for Canadian Poutine dish

Poutine is a simple dish traditionally from Québec, Canada. It is traditionally made with French fries, topped with fresh mild white cheddar curds (quite unlike American white cheddar which is quite sharp) and with a tangy and salty brown gravy poured on top of it all. It looks something like this:

It's easy to make when you like up in Québec, as the gravy can be purchased in any grocery store. But I live in the USA now, and there is no such thing as poutine gravy here. For the cheese I use Monterey Jack cheese, which is close enough. I've tried to whip up my own gravy multiple times, but it's never been quite right. Here is how I usually go about it:

1. 
   

   Start with chicken stock.

   
   


2. 
   

   Thicken with flour or starch.

   
   


3. 
   

   Add some pepper, salt (if needed, usually it's pretty salty already).

   
   


4. 
   

   Add something for tang, like a bit of barbecue sauce or ketchup.

   
   


5. 
   

   Maybe throw in a few spices, like garlic or onion powder.

   
   

I was just wondering if anyone has ideas to make this more palatable, e.g., other ingredients, or any cooking suggestion.