I branched out on this recipe (I'm not a huge roast fan) but it actually turned out delicious! I cooked it on low all day and by dinner time it was so tender it just fell apart and soaked up all of the juices.
3 pounds beef roast 1/3 cup molasses 1/3 cup dijon mustard 1 teaspoon garlic powder 2 tablespoons white vinegar
Dump meat into crockpot. Top with molasses, dijon, and vinegar. Toss in the garlic powder. Using tongs, flip the meat over a few times to coat it nicely with the sauce. Cover and cook on low for 6-8 hours or on high for about 4.