Cook noodles according to package directions, omitting salt and fat; drain.
While noodles cook, heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add steak; sauté 5 minutes, browning on all sides.
Remove from pan; cover.
Melt butter in pan over medium-high heat. Add shallots and mushrooms; sauté 4 minutes.
Add garlic; sauté 30 seconds. Stir in Worcestershire Sauce. Sprinkle flour over mushroom mixture; cook 1 minute, stirring constantly.
Gradually add broth, stirring constantly with a whisk.
Add pepper, salt, and thyme sprigs.
Bring to a boil; cook 2 minutes or until thickened. Return beef to pan; cook 1 minute or until thoroughly heated.
Discard thyme sprigs. Garnish with thyme leaves, if desired.
by The Savvy Kitchen