Cover broiler pan with aluminum foil.
Set broiler pan about 4 inches from heat source.
Preheat broiler.
Place peppers on aluminum foil.
Broil 15 to 20 minutes until blackened on all sides, turning peppers every 5 minutes with tongs.
To steam peppers and loosen skins, place blackened peppers in paper bag.
Close bag; set aside to cool about 20 minutes.
To peel peppers, cut around core, twist and remove.
Cut peppers in half lengthwise; place pepper halves on cutting board.
Peel off skin with paring knife; rinse under cold water to remove seeds.
Lay pepper halves flat and slice lengthwise into 1/4 inch strips.
Transfer pepper strips to glass jar.
Add garlic, oregano and oil.
Close lid; shake to blend.
Marinate at least 1 hour.