Preheat oven to 500°.
Remove stem ends of poblano chiles, leaving chiles whole; discard seeds and membranes. Set aside.
Place tomatoes, onions, and garlic on a foil-lined jelly-roll pan. Bake at 500° for 30 minutes (garlic should be lightly browned; remove before 30 minutes, if necessary). Let vegetables cool 10 minutes. Peel tomatoes and garlic; discard skins. Remove cores from tomatoes. Place tomatoes, garlic, onion, and chipotle chile in a food processor, and process until smooth. Strain through a sieve into a large saucepan; discard solids. Add water, oregano, and bay leaf to pan; bring to a boil. Reduce heat, and simmer, uncovered, 40 minutes or until reduced to 2 cups. Remove from heat; discard oregano and bay leaf. Add 1/4 teaspoon salt and dash of pepper to tomato mixture; set sauce aside, and keep warm.
Combine corn and next 6 ingredients (corn through dash of pepper) in a bowl; stir well. Pack 3/4 cup corn mixture into each poblano chile. Place stuffed chiles on foil-lined jelly-roll pan. Bake at 500° for 20 minutes or until chiles are blackened, turning after 10 minutes; peel chiles.
Spoon 1/2 cup tomato sauce onto each of 4 plates, and top with stuffed chiles. Garnish with whole chives and cilantro sprigs, if desired.