- Heat canola oil in a 12-inch skillet and heat over medium heat. Add beef and stir-fry 2 to 3 minutes, or until just starting to brown. Remove beef from skillet and add the white halves of the scallions to the skillet. Sauté 2 to 3 minutes, or until starting to soften.
- Add the beef, Kikkoman Teriyaki Takumi Sauce, 1 teaspoon salt and 1/2 teaspoon black pepper to the skillet, stir to combine, and bring to a gentle boil. Reduce heat to low and simmer 5 to 7 minutes, or until heated through and meat is at desired doneness. Remove from heat.
- Meanwhile, to prepare the udon noodles, bring a large pot of unsalted water to a rapid boil over high heat. Add noodles; bring back to a boil, and cook, stirring occasionally, until they just begin to soften, about 3 to 5 minutes. Drain noodles in a colander and rinse under cold running water. Transfer noodles to beef mixture and toss to combine.
- Serve in individual soup-style bowls, garnished with green tops of the scallions.