This easy slow-cooker pot roast has a secret ingredientpepsibut if you don't have that brand, any other cola will work. Some pundits believe the acid in cola helps to tenderize a tough cut of meat but, more probably, a long, slow cook is what does it. Add some sliced onions, carrots, celery, or potatoes to the pot roast for a complete meal. Cook it until it's tender and serve with gravy made by thickening the cooking juices. Or skip the vegetables and cook the meat until it's falling apart and shred it for sandwiches in the same way you would do for pulled pork. Serve the pulled pot roast with barbecue sauce or horseradish sauce if desired.