In a 2-quart saucepan combine rhubarb and cranberry-apple juice concentrate. Bring to boiling; reduce heat. Cover; simmer for 15 minutes or until rhubarb is very tender. Strain mixture into a 2-cup liquid measure, pressing out the liquid with the back of a spoon. Add water, if needed, to equal 1-1/4 cups liquid. Discard pulp.
In the same saucepan combine cornstarch and water. Stir in rhubarb liquid. Cook and stir until thickened and bubbly. Cook 2 minutes more. Stir in honey, Dijon-style mustard, and wine vinegar. Heat through. Use immediately or cool, cover, and chill for up to 5 days. Brush on burgers or chicken during the last 15 minutes of grilling. Makes 1-3/4 cups (10 servings).