1.Preheat oven to moderate, 180°C. Line an oven tray with foil.
2.Brush tortillas with half oil. Cut each into 6 rectangles. Arrange on tray and bake for 4-6 minutes, turning once. Allow to cool.
3.In a bowl, combine kidney beans, chilli powder and remaining oil. Season to taste.
4.In a small bowl, combine avocado, onion, coriander, chilli and lime juice. Season to taste.
5.Arrange baked tortilla pieces on a serving platter. Top each with 1 teaspoon kidney bean mixture, followed by a little avocado mixture, sour cream and diced tomato. Garnish with a coriander leaf.