In a large skillet over medium-high heat, bring the first four ingredients for the beef to a simmer. Stir in the beef, reduce the heat to medium, and simmer until cooked through, stirring occasionally, about 7 minutes. Drain the excess liquid, then stir in the soy sauce, fish sauce, and vinegar. Cover to keep warm.
In a large bowl, stir together the first six ingredients for the waffles until well blended. Fold in the rice, carrot, and scallions. Coat a waffle iron with cooking spray and heat it according to the manufacturer's instructions. Ladle on 1/2 cup batter (the amount may vary depending on the size of your iron). Cook until golden brown, about 5 minutes. Repeat with the remaining batter. Serve each waffle topped with a scoop of the beef, a sprinkle of cilantro, and lime wedges.