In a large skillet ( I use a Lodge Cast Iron Skillet)  heat shortening and butter, next,  whisk in the flour.  (This is a simple roux.)  Keep whisking over medium heat so oil and flour mixture blends and thickens.  Let the roux(mixture) cook until it gets thick and starts to get a light mellow vanilla color.  (If you don’t let it cook long enough and it stays white it will taste like flour or raw dough.)  Whisk in the chicken stock and milk then continue whisking until the roux is nice and creamy thick.  If it becomes too thick add a bit more broth a milk until desired consistency.

Now, add the strained diced tomatoes and continue to stir. Let this simmer slowly together for a few minutes, then taste and add the salt, pepper and a bit of sugar. (I add sugar to bring out the yum in the tomatoes!) If you have homegrown tomatoes on hand then dice a medium-sized one of those instead, it will taste amazing!