Roast chiles over gas flame, turning frequently with tongs, until charred on all sides, about 5 minutes each.  Place in a plastic bag, set aside to allow steaming for 10 minutes.  Using the  back of knife, scrape and remove poblano charred skin.  Make a 2-inch slit in each poblano and scrape out seeds with a small spoon.  Tuff each poblano with 1-2 slices of cheese and set aside.

Combine broth, oil and rice in a 5-quart pan over medium heat.  Season with salt.  Bring to a boil, reduce heat and cover.  Cook for 10 minutes, stir in frozen vegetables and arrange stuffed poblanos in rice.  Cover and cook for 10 more minutes or until rice is tender and fluffy.

Serve each poblano on a serving plate with a side of rice.