Before cooking, follow on-pack instructions to rinse and pick over uncooked barley.
Heat half the oil in a pan and cook chorizo over medium heat until crisp. Remove to a paper towel lined plate.
Wipe out excess fat from pan and add remaining oil. Cook onion and garlic until tender. Return chorizo to pan with the stock, tomatoes, uncooked barley and oregano. Bring to the boil, then stir in capsicum and corn. Reduce to a simmer and cook for 35-40 minutes until vegetables and barley are tender. Season to taste.
Serve soup with sour cream, sliced chilies and coriander.