For a healthier take on ramen, substitute sweet potato zoodles for the traditional wheat noodles. The shortcut broth has loads of flavor without taking hours to cook. You can create the zoodles with a spiralizer or mandoline; we used the thickest julienne blade on the Benriner Cook Help and the fine shredder (3- by 3-mm.) blade on the Paderno 4-Blade Spiralizer.
Cut sweet potatoes into smaller pieces if needed to fit in a spiralizer, then crank through to create spaghetti-size coils (save leftover chunks of sweet potato for other uses). Tear coils into manageable lengths. Heat 2 tbsp. oil in a large frying pan over medium-high heat, then add half of sweet potatoes. Cook, tossing lightly, until lightly wilted and just tender to bite, 5 to 7 minutes. Transfer to a paper towel-lined plate and set aside. Repeat to cook remaining sweet potatoes.
Meanwhile, put eggs in a small saucepan filled with water. Bring to a boil, then remove from heat and leave eggs in pan 5 minutes. Drain and fill pan with ice water. When cool, peel eggs and cut each in half lengthwise.
Pour broth, ginger, mirin, soy sauce, dashi, and miso into a large pot. Bring to a boil over medium-high heat. Divide broth among four large bowls; add sweet potatoes, eggs, green onions, and bean sprouts to each. Drizzle with chili oil.
* Find mirin and dashi at grocery stores in the Asian-foods aisle or online, and miso in grocery stores' refrigerated foods aisle.
Cut sweet potatoes into smaller pieces if needed to fit in a spiralizer, then crank through to create spaghetti-size coils (save leftover chunks of sweet potato for other uses). Tear coils into manageable lengths. Heat 2 tbsp. oil in a large frying pan over medium-high heat, then add half of sweet potatoes. Cook, tossing lightly, until lightly wilted and just tender to bite, 5 to 7 minutes. Transfer to a paper towel-lined plate and set aside. Repeat to cook remaining sweet potatoes.
Meanwhile, put eggs in a small saucepan filled with water. Bring to a boil, then remove from heat and leave eggs in pan 5 minutes. Drain and fill pan with ice water. When cool, peel eggs and cut each in half lengthwise.
Pour broth, ginger, mirin, soy sauce, dashi, and miso into a large pot. Bring to a boil over medium-high heat. Divide broth among four large bowls; add sweet potatoes, eggs, green onions, and bean sprouts to each. Drizzle with chili oil.
* Find mirin and dashi at grocery stores in the Asian-foods aisle or online, and miso in grocery stores' refrigerated foods aisle.