Heat your grill to medium high. Grill the tomatoes and green pepper on all sides until charred.Set tomatoes aside and put roasted green pepper in a brown paper bag and let rest for 10 minutes.
Trim cores from tomatoes and coarsely chop. Put chopped tomatoes in a stainless steel bowl. Remove green pepper from bag and gently remove charred skin. Cut away core, remove seeds and coarsely chop. Add green pepper to bowl of tomatoes.
Add remaining ingredients to the bowl and marinate overnight.
Put all of the ingredients in a blender (for finest texture) or a food processor (for coarser texture) and puree until smooth. Adjust vinegar, salt and pepper to taste. Return to refrigerator to thoroughly chill.
Serve with croutons or diced cucumbers and avocado.