1) Combine sweet potatoes, onion and taco seasoning in large nonstick skillet over medium heat. Add water. Cover and cook 8 to 10 minutes or until crisp-tender and water has almost evaporated, stirring once. Stir in oil; continue cooking, uncovered, 4 to 6 minutes or until potatoes are tender and begin to brown, stirring occasionally. 2) Meanwhile, combine sour cream and hot sauce in small bowl. Set aside. 3) Add beef to potato mixture. Continue to cook 5 minutes or until beef is heated through, stirring occasionally, adding 1 to 2 tablespoons water, if needed to avoid sticking. 4) Garnish with cilantro, as desired. Serve with sour cream mixture.