Step 1: If using poblano peppers, cut them in half lengthwise, and scrape out the seeds. If using bell peppers, cut off the tops about 1/2 inch below the stems. Scrape out the veins and seeds, taking care not to puncture the bottoms.
Step 2: Drain the beans, place them in a colander, rinse under cold running water, then drain again.
Step 3: Heat 2 tablespoons of the olive oil in a nonstick skillet over medium heat. Add the onion, garlic, jalape–os, red bell pepper, cilantro, pumpkin seeds, if using, and cumin and cook until golden brown, about 4 minutes. Stir in the beans, hot sauce, and 2 cups of the cheese. Taste for seasoning, adding salt, pepper, and/or more hot sauce as necessary. Spoon the bean mixture into the hollowed-out peppers. Sprinkle the remaining cheese on top, dividing it evenly among the peppers. Drizzle the remaining 1 tablespoon of olive oil over the cheese.
Step 4: Set up the grill for indirect grilling and preheat to medium. If using a gas grill, place all of the wood chips or chunks in the smoker box or in a smoker pouch and preheat on high until you see smoke, then reduce heat to medium. If using a charcoal grill, preheat it to medium, then toss all of the wood chips or chunks on the coals.
Step 5: When ready to cook, place the peppers in the center of the hot grate, away from the heat. Cover the grill and cook the peppers until they are tender and the cheese is browned and bubbling, 30 to 40 minutes. Use a spatula to transfer the peppers to a platter or plates and serve at once.
Hulled pumpkin seeds (pepitas) are available at natural food stores and Hispanic markets.