Nonstick vegetable oil spray
3 ¼ pounds red-skinned sweet potatoes (yams), peeled, cut into ¾-inch cubes
5 tablespoons extra-virgin olive oil, divided
2/3 cup thinly sliced shallots (3 large)
1 red bell pepper, very thinly sliced
1 jalapeno chili, seeded, thinly sliced
1 ½ tablespoons mirin (sweet Japanese rice wine)
4 large green onions, chopped
2/3 cup chopped fresh cilantro
Preheat oven to 400° F. Spray 2 large rimmed baking sheets with nonstick spray. Toss potatoes with 3 tablespoons oil in large bowl; divide between sheets. Sprinkle with salt and pepper. Roast 10 minutes. Reverse sheets and roast until potatoes are tender and browned, stirring occasionally, about 15 minutes longer. Transfer to large bowl.
Heat 2 tablespoons oil in large skillet over medium-high heat. Add shallots and sauté 3 minutes. Add bell pepper and chili; sauté until beginning to soften, about 3 minutes. Add mirin; simmer 1 minute. Mix in green onions and stir 15 seconds. Scrape mixture over potatoes. Mix in cilantro. Season to taste with salt and pepper. Serve warm or at room temperature.