4sandwich rollsRecommended: brioche buns or pretzel rolls
Place chopped onion, carrot, and garlic in the slow cooker.
Preheat a saute pan on the stovetop over medium-high heat. Once the pan is preheated, coat with olive oil to prevent sticking. Brown each of the 4 long sides of the short ribs for about 2 minutes per side. You can brown them in batches if all of the ribs you have won't fit in the pan at one time.
Transfer the short ribs to the slow cooker.
Add beer to the slow cooker. Then add the beef stock until about one-fourth to half of each short rib is covered with liquid. Depending on the shape and size of your slow cooker and short ribs, you might need more or less than a half cup of stock.
Add Montreal steak seasoning over the top of everything in the slow cooker.
Cook on low for 8 hours.
Remove from the slow cooker and pull the meat apart with a fork. Toss with BBQ sauce. Serve on sandwich rolls.