For the grillades:Pat the chuck cubes dry if needed and season well with salt and pepper, tossing to coat. Working in batches, brown the beef well in a Dutch oven with a little oil. Set aside. Wipe out the pot with a paper towel. Melt the bacon fat over medium heat. Add the flour, whisking constantly until the mixture (a roux!) is fragrant and a medium brown color. Turn the heat to low and toss in the peppers, onions and celery. Stirring occasionally, cook until the vegetables are wilted.
Usually at this point I throw everything, the beef, the roux/veggie mixture and all the remaining ingredients in a large slow cooker and wander off. I recommend you do this, too. After all, it’s Christmastime and I’m sure you’re busy. Cook on low for 8 or 9 hours. Cool and refrigerate until needed. Reheat on high until hot and switch to warm.
If you have no slow cooker, you can finish this either on the stovetop or even covered in a 300° oven if your cooking vessel is oven safe. To cook on the stovetop/in the oven, add everything to the pot and cook on very low for 2 ½ hours or until the beef is beyond fork-tender, adding more beef stock as necessary to make sure it doesn’t dry out. Check for seasoning and adjust if necessary. If making ahead, cool and refrigerate until needed. Reheat carefully on a low simmer until hot through. Serve over Extra Creamy Grits below.
For the extra creamy grits:In a heavy-bottomed pot, bring the milk and salt to a low boil. Quickly add all the grits and whisk in very well. Bring back to a boil while whisking. Turn heat to low, cover and simmer for 7 or 8 minutes, whisking occasionally. (You must whisk occasionally if making this many grits at once, otherwise you will have chunky grits. That’s absolutely not the goal.) When grits are tender, turn off the heat and with a wooden spoon stir in the cheese a handful at a time. Cover to keep warm on the stove, or, if making ahead, scrape into a buttered casserole dish and allow to cool. Let come to room temperature if possible before reheating, covered, at 350° until hot. This makes enough grits to serve under the entire recipe above.