In a large saucepan, saute onions in oil until tender. Add the broth, corn, potatoes, cream, chipotle pepper and salt. Bring to a boil. Reduce heat; simmer, uncovered, for 3-5 minutes., For dumplings, in a small bowl, combine the flour, cornmeal, baking powder and salt. Stir in milk and cheese just until moistened. Drop by tablespoonfuls onto simmering chowder., Cover and simmer for 20 minutes or until a toothpick inserted in the center of a dumpling comes out clean (do not lift cover while simmering).