Peanut or canola oil, for shallow frying
1 pound boiling potatoes, peeled and cut into thick 2 by 1 by 1-inch fries
1 head cauliflower (1 3/4 pounds), cut into delicate florets
1 tablespoon peeled finely chopped fresh ginger
1/4 teaspoon ground turmeric
3/4 to 1 teaspoon salt
1/4 teaspoon cayenne
1 teaspoon ground cumin
1 teaspoon ground coriander
3 tablespoons water
2 to 3 tablespoons coarsely chopped cilantro leaves