Preheat oven to 425°F (220°C).

Place peppers on baking tray and roast in preheated oven for about 40 to 45 minutes, until skins are charred and black. Remove peppers from oven and place in bowl and immediately cover with plastic wrap. Reserve.

While peppers are in oven, prepare a second baking tray. Pour 1/2 tablespoon (7 ml) of the olive oil on bottom of baking tray.

Place tomatoes and shallots on tray cut side down with garlic cloves and oregano sprigs. Sprinkle vegetables with 1/4 teaspoon (1 ml) of the salt. Once peppers are out of oven, turn oven temperature down to 375°F (190°C) and place tomatoes in oven. Roast for about 45 minutes, until tomato skins are shriveled and slightly darkened. Remove from oven and carefully remove and discard tomato, shallot, and garlic skins. Discard oregano sprigs as well.

Remove all skin and seeds from red peppers and discard.

Place peppers, tomatoes, shallots, garlic, remaining salt, pepper, and chicken broth in blender jar. Cover blender jar. Holding cover firmly in place, pulse blender on low about 10 times. Turn blender to low for about 30 to 40 seconds until completely blended. Pour out into saucepan to reheat and adjust seasonings. For a thinner soup, simply stir in more chicken broth.