1.Heat the oil in a deep frying pan and add the onions. Cook over a medium heat for 2-3 minutes or until onions are just softened. Add the garlic and cumin and cook for 1-2 minutes stirring, until fragrant; add the diced capsicum and corn. Cook for 3 minutes or until corn is tender, then add the beans cook for a further 2 minutes, stirring occasionally. Remove from heat and set aside to cool.
2.Gently fold the canned beans and lime juice through the vegetables then transfer to a serving platter lined with the rocket leaves.
3.To make dressing; combine all ingredients in a small bowl. Serve the salad with the dressing.
Chipotle chillies in adobo are available from selected delicatessens and large greengrocers.