In a large sauce pan, cook onions and fruit on medium/high heat until onions are lightly caramelized and translucent. Approx 4-6 mins.
Add brown sugar and worchestershire sauce, seasonings, ketchup and molasses. Continue cooking for 5 mins until sugar has dissolved.
Add vinegar and cook for 2 mins. Add pan drippings or stock and remainder of ingredients.
Stir well to combine and turn heat down to low. Sauce should simmer and bubble gently.
Cook for 15 mins stirring often to ensure nothing is stuck to the bottom. Add a few spoons of water if it begins to thicken too much.
After fruit has completely broken down, transfer sauce to a blender or use a hand blender directly into the pot being careful as the sauce and pot will be hot.
Blend until completely smooth. If you want a thinner sauce, press and strain the sauce to remove the large pieces of fruit and onion and add 1 tbls of cornstarch and water slurry.
Continue to cook for an additional 5-10 mins until sauce is rich with flavor and color. Taste and adjust for salt and sweetness.
Store in an airtight container in the fridge or jar using the canning technique and it will last you throughout the summer.