How to Make It
In a large saucepan, cover the beans with cold water and bring to a boil. Reduce the heat to moderate and simmer until the beans are just tender, about 45 minutes. Drain the beans.
In a large cast-iron casserole, heat the oil until shimmering. Add the bacon and cook over moderate heat, stirring occasionally, until golden, 5 minutes. Add the garlic and cook until fragrant, 1 minute. Stir in the onion, bell pepper, chile, cumin, oregano, paprika, 1 tablespoon of salt and 1 teaspoon of pepper. Cook, stirring occasionally, until the vegetables soften, 5 minutes. Add the tomatoes and cook, stirring, until they begin to break down, about 2 minutes.
Add the beans and chicken stock to the vegetables and bring to a boil over high heat. Cover partially and cook over moderate heat for 45 minutes, stirring occasionally. Add the pumpkin and cook until tender, about 15 minutes.
Meanwhile, grate the corn on the large holes of a box grater set in a shallow bowl; you should have about 1 1/4 cups. Add the corn and its juices to the stew along with the basil and simmer over moderate heat until thickened, about 10 minutes longer. Season with salt and pepper and serve.
The ají cristal chile is a medium-hot yellow pepper native to Chile.