Healthy Seven Layer Dip

1 pound plum tomatoes, seeded and finely chopped 1 green onion, finely chopped 1 clove garlic, finely chopped 1/2 jalapeno chile, seeds and ribs removed, finely chopped 2 tablespoons fresh lime juice Salt 1 teaspoon canola oil 1 small onion, finely chopped 1/2 teaspoon no-salt-added chili powder 1 can (15-ounce) no-salt-added pinto beans, rinsed and drained Pepper 1 ripe Hass avocado, pitted and peeled 2 tablespoon chopped fresh cilantro 1 cup (from 2 ears) fresh corn kernels 1 large red pepper, finely chopped 4 ounce reduced-fat sour cream 1 1/2 ounces low-fat Cheddar cheese, shredded