Fill a large pot with lightly salted water and bring to a boil over high heat. Stir in the risoni and return to a boil. Cook the pasta uncovered stirring occasionally until the pasta has cooked through but is still firm to the bite; about 10 minutes. Drain.
Place the drained risoni in a large salad bowl and fold in the red capsicum, yellow capsicum, spring onions, red onion, chickpeas, kidney beans, black beans, corn, coriander, salt and pepper.
Pour the lime juice and oil over the salad, toss to coat then refrigerate at least 2 hours to chill before serving.
Th black beans used in this recipe are the South American ones not the Asian ones. You should be able to find them with Mexican ingredients.