Wrap potatoes in wet paper towels; microwave until slightly tender, about 7 minutes. Cut into bite-size pieces.
Heat olive oil in a skillet over medium-high heat. Add cumin seed; cook and stir until golden, about 1 minute. Add potatoes, salt, curry powder, gram flour, cayenne pepper, and ground ginger. Cook and stir until toasted and crispy, 8 to 10 minutes.