Place cherries in a colander. Run cold water over cherries to partially thaw; drain well. Set aside.
In a 12-inch skillet cook mushrooms, sweet pepper, onion, and 1 tablespoon of the sage in hot oil about 7 minutes or until tender, stirring occasionally. Add pot roasts and juices, cherries, and balsamic vinegar to the skillet. Bring to boiling; reduce heat. Simmer, uncovered, for about 10 minutes or until heated through and juices thicken slightly, stirring occasionally. Sprinkle with remaining sage; stir to combine.
Meanwhile, prepare potatoes according to package directions. Serve with pot roast. Makes 4 to 6 servings.