In a large bowl, combine the brown gravy mix and cornstarch. Gradually whisk in the brewed coffee to ensure there are no lumps. Next, add the red wine, soy sauce, Worcestershire sauce, minced garlic, and black pepper. Set the mixture aside.
Heat oil in a large skillet over medium-high heat. Add the roast and sear it on all sides until browned. Once seared, transfer the roast to a 7+ quart crockpot.
Layer the chopped carrots, onions, and mushrooms over the roast in the slow cooker. Pour the prepared gravy mixture over the top, ensuring the roast and vegetables are evenly coated. Cover the crockpot with its lid.
Set the slow cooker to low and cook for 8 to 10 hours, or until the roast is fork-tender and easily shreds.
Once cooked, remove the roast from the slow cooker and shred it into chunks using two forks. Stir the vegetables and gravy together to combine.
Serve the shredded pot roast, topped with the rich gravy and vegetables, over mashed potatoes or cauliflower mash for a complete meal.