Bill, 'ketchup maison' is a must. It's a tomato/fruit chutney that compliments a tourtiere perfectly. Plenty of retailers stock it this time of year... Sorry I can't tell you where to get the best, but I'm sure other posters could.
I like it with a side salad - spinach or mesclun, with a nice vinegar dressing to cut the richness of the tourtiere. And of course a spoonfull or two of a tomoato chutney/chili - again to cut the richness of the main