Cook potatoes in boiling water to cover 25 minutes or until tender. Drain and let cool slightly. Cube potatoes; cover and set aside.
Cut chiles in half lengthwise; remove and discard seeds andmembranes. Place chiles, skin side up, on a baking sheet, andflatten with palm of hand. Broil 5 1/2 inches from heat (with electric oven door partially opened) 12 to 15 minutes or until charred.Place in ice water until cool; peel and discard skins. Coarselychop chiles.
Coat a large nonstick skillet with cooking spray; place skillet over medium-high heat until hot. Add onion, garlic, oregano, and cumin; saute 3 minutes or until onion is tender. Add cubed potato; cook until golden, turning potato gently with a metal spatula. Add chopped chile, salt, and 1/4 teaspoon pepper; cook just until thoroughly heated. Transfer to a serving bowl, and sprinkle with cilantro. Serve immediately.