1.Heat oil in a large saucepan over medium heat; cook onion, capsicum and mushrooms, stirring, for 5 minutes or until softened. Add taco seasoning; cook, stirring, 1 minute or until fragrant.
2.Add beans, corn, and salsa to pan; bring to the boil. Reduce heat to low; simmer, 5 minutes or until sauce thickens. Season to taste.
3.Meanwhile, preheat grill (broiler).
4.Place corn chips in a large ovenproof dish (or into four ovenproof serving dishes); sprinkle with cheese. Grill about 3 minutes or until cheese melts.
5.Serve corn chips immediately, topped with bean mixture, guacamole, sour cream and coriander.