BBQ Sauce:
Using a blender mix the onion and water into a puree.
Heat a medium sauce pan over a medium heat and add the olive oil.
Pour in onion puree and cook until slightly browned.
Add the remaining ingredients.
Mix thoroughly and simmer for about 20 minutes.
For the Boston Butt:
Inject the Boston Butt
Make cuts crosswise on the fat cap and covered the Boston Butt with Yellow Mustard and your favorite rub.
Set the Big Green Egg up using the plate setter for indirect heat and heat the egg until the dome measured 350°.
Place wood chips or chunks over the warm coals (I used hickory and pecan wood).
At the 3 hour mark put the pork in an aluminum pan and cover with aluminum foil.
Let this cook for another 2 hours until the internal temp reached 195°.
Chop up the pork and serve.