Heat the olive oil in a large nonstick skillet over medium heat. Add the baby bell peppers in a single layer and cook, turning, until the skins blister and start browning, about 8 minutes. Transfer to a plate.
Add the onion, poblano, garlic, cumin, oregano, ancho and chipotle chile powders and 1 teaspoon salt to the skillet. Cook, stirring, until the onion and poblano are tender, about 8 minutes. Increase the heat to medium high and add the pork. Cook, breaking up the meat with a wooden spoon, until no longer pink, about 6 minutes. Remove from the heat; let cool.
Meanwhile, preheat the oven to 425 degrees F. Make a slit in each baby bell pepper with a paring knife, cutting from stem to tip. Crumble the meat mixture into small bits, then stir in the cilantro and cheese. Stuff 2 to 3 teaspoons of the meat mixture into each pepper using your fingers or a small spoon; transfer to a baking sheet. (The peppers can be stuffed up to 4 hours ahead; cover and refrigerate. Bring to room temperature before baking.)
Bake until the peppers are hot and the cheese melts, about 10 minutes. Season with salt and serve with lime wedges.
Photograph by David Malosh
Recipe courtesy of Food Network Magazine