Char the chiles until the skins are well blistered on all sides. To loosen the skin so it peels away easily, place freshly blistered chiles in a covered bowl or a plastic bag. Set aside and let the chiles “steam” for about 10 minutes. Gently peel away the loosened skin.
Slice a slit down the center of each chile. Cut away the bulk of the seeds near the stem, aiming to keep the stem as intact, mostly for show. Set the prepared chiles aside on a plate.
In a medium skillet heat the olive oil. Add the onion, serrano chile, carrots, and garlic. Cook over medium heat, stirring occasionally until the onion is translucent. Stir in the chickpeas, cumin and oregano. Add the broth. Using the back of a fork or a potato masher, mash the beans with the broth to heat through. Remove from the heat and stir in the cheese and salt. Taste and season with more salt if needed.
Preheat the oven to 350° F. Fill the chiles with the bean mixture. (You may have some filling left depending on the size of the chiles.)
Place them in a casserole dish, seam side down.
Bake about 20 minutes, until the rellenos are heated through.
If you wish, sauté the diced red pepper in a bit of oil. Otherwise leave the red pepper raw.
To serve: Spoon about 2 tablespoons of the crema into the corner of a small plastic sandwich bag. Cut a tiny hole in the corner. Squeeze the bag with gentle pressure to draw the white stripes over the chiles. Sprinkle with diced red pepper.
Serve with tortillas or steamed rice.