Combine pureed blueberries and vegetables, vinegar, honey, molasses, ketchup, and spices in a large heavy, nonreactive saucepan. Simmer over medium heat until the sauce is thick and the vegetables are soft.
Return sauce to blender and puree until completely smooth. Sauce should be thick but easy to pour. Check the seasoning and correct to taste. Store in clean jars in the fridge. Sauce will last for several weeks.
Recipe Notes
Adapted from Steve Raichlen’s “Barbecue Bible: Sauces Rubs and Marinades”