In a skillet, heat oil over medium heat. Add onion and celery and cook, stirring, until softened, about 5 minutes. Add rice, salt, and pepper and cook, stirring, for 1 minute. Add soup and broth and stir until smooth. Stir in beans and transfer to slow cooker.
Place 2 clean tea towels, each folded in half (so you have 4 layers), over top of stoneware, to absorb the accumulated moisture (I only had 2 towels with 2 layers, worked fine). Cover and cook on Low for 8 hours or on High for 4 hours, until hot and bubbling.
Remove tea towels. Add jalapeno pepper, if using, green chilies, and cheese. Cover and cook on high for 20-30 minutes, until cheese is melted and mixture is hot and bubbling.