Ingredient selection for Canadian Poutine dish
Hello @Phrancis and welcome to Seasoned Advice! Poutine gravy is a beef gravy made with beef or veal stock. Here is a link to a  recipe . There are many other recipes online, as well.

You can buy the prepared sauce online  here  or a gravy mix on  Amazon .

By the way, you were on the right track, just not quite there yet! :)