Heat the oil in a large nonstick skillet over medium-high heat. Add the mustard seeds; cook for 1 minute. Add potato and next 7 ingredients (potato through red pepper), stirring until blended. Add water; bring to a boil. Cover, reduce heat, and simmer 20 minutes or until tender. Uncover and cook 4 minutes or until liquid evaporates, stirring frequently. Serve over rice.