Brush the corn with olive oil then grill for 10-15 minutes, turning regularly, until the corn is golden brown and caramelized on all sides. Remove and allow to cool slightly before slicing the kernels off the cob.
Optional: Fry the beans in a splash of oil in a large pan for 2-3 minutes. Season with salt, pepper and garlic powder.
Chop the vegetables into small dice then add to a large bowl.