Heat oil in large non-reactive saucepan (or pot) over medium heat. Add: Onion, garlic and bell pepper and sauté until soft but not brown, about 4 minutes.
Stir in: ketchup, tomato sauce, water, vinegar, Worcestershire sauce, lemon juice, pineapple juice (if using), hot sauce, liquid smoke, molasses, sugar, both mustards and black pepper. Bring to boil. Reduce heat to low and simmer uncovered until thickened, about 15 min. Stir often to prevent scorching.
Remove from heat and taste for seasoning, adding salt and vinegar, hot sauce and sugar as needed.
Transfer to a bowl and cover tightly. Sauce will last in refridge for several weeks.
Options: When finished with the above, the sauce will be thick and lumpy from the veggies in it. You can then puree it in a blender to make the sauce smooth.