Position the oven racks 6 to 8 inches from the heating element and preheat the broiler.
Cut the heirloom tomatoes in half and score the skin with a sharp paring knife. Toss the tomatoes, 2 poblanos and 1 red onion cut into quarters with the olive oil, set on a rimmed baking sheet and place in the oven. Broil until the skin on the tomatoes and poblanos begin to blister. Remove from the oven and set aside until cool enough to handle. Remove and discard the skin from the tomatoes. Remove and discard the seeds and stem from the poblanos and cut into chunks. Add the tomatoes, poblanos and onions to a large bowl and using a hand blender puree the roasted vegetables. Alternatively you can use a blender. Set aside.
Finely dice the jalapenos and red bell pepper and add to the bowl with the puree. Add the remaining ingredients and mix well.
Set the Pico de Gallo aside for at least one hour to allow the flavors to meld together.
Serve immediately or store in an air-tight container in the refrigerator for up to 3 days.
Yield: about 6 cups