In large pot, heat oil over medium heat. Add celery and onion and cook, stirring occasionally, until golden, about 10 minutes. Stir in carrots, potatoes, bay leaves, bouillon cubes, cumin, thyme and 31Ú2 cups water and bring to a boil. Reduce heat to low, cover and simmer gently until vegetables are tender, 25 to 30 minutes.
Meanwhile, in food processor or blender, puree tofu until smooth. Stir into soup along with corn, salt and pepper. Reduce heat to low and simmer, uncovered, 10 minutes. If time allows, let chowder stand off heat for an hour or so, then rewarm over very low heat. Remove bay leaves before serving.