Trim fat from beef. Cut beef into 3/4-inch cubes. Place flour in a resealable plastic bag. Add beef cubes and shake to coat. Heat oil over medium-high heat in a large skillet with a lid. Cook half of the beef cubes in hot oil until browned. Remove from skillet. Add remaining half of beef cubes, onion, carrot, celery, and garlic to skillet; cook until beef is brown, adding additional oil if necessary. Drain off fat. Return all meat to the skillet.
Stir in broth, oregano, and pepper. Bring to a boil; reduce heat. Simmer, covered, for 1 1/4 to 1 1/2 hours or until meat is desired tenderness.
Stir frozen noodles into skillet. Bring to a boil; reduce heat. Cook, uncovered, for 25 to 30 minutes or until noodles are tender, stirring occasionally. Serve over Skin-On Mashed Potatoes.
[Cleaning tip: Once the stove top is cool, wipe up any oil splatters or spills with Clorox® Disinfecting Wipes*. Rinse hands once complete.]
For Skin-On Mashed Potatoes: Place potatoes into a large pot and cover with water; stir in the 1/2 teaspoon salt. Bring to a boil over high heat, then reduce heat to medium-low, cover, and simmer until tender, about 20 minutes. Drain. Place drained potatoes, milk, butter, sour cream, the 1/4 teaspoon salt, and the 1/8 teaspoon pepper in a large bowl. Mix well with an electric mixer on medium speed.