In a large pot or skillet add 2 tablespoons of vegetable oil on high heat.

Season the pot roast with the kosher salt and ground black pepper.

Add the pot roast to the pan and brown on both sides, about 3-5 minutes on each side.

Add the meat to the slow cooker.

Add the onions into the pan you browned the beef in and cook for 1-2 minutes.

If you have space around the meat in the slow cooker, add in some small potatoes and carrots.

Top the beef with the onions, garlic, thyme, and bay leaf.

In a small cup, add the beef base (if using) to the balsamic vinegar and whisk.

Top the beef with the balsamic mixture, red wine, and brown sugar.

Cook on low for 6 to 8 hours.

Remove the bay leaf before serving.

To make the sauce into a glaze, strain the liquid out after it is done cooking.

Spoon off the fat and discard.

Add the remaining sauce to a small pan and cook in a saucepan on medium heat until thickened, about 8-10 minutes.

If you want a stronger balsamic flavor, add in another 2 tablespoons of balsamic vinegar to the sauce before cooking it down in the saucepan.