CUT meat into 3/4-inch-thick slices; flatten to 1/2-inch thickness. Season with garlic powder and black pepper. Heat oil in large nonstick skillet on medium heat. Add meat; cook 2 min. on each side or just until done. Transfer to platter; cover to keep warm.
ADD beans to skillet; cook and stir 4 to 5 min. or until crisp-tender. Transfer to platter with meat.
COOK and stir mushrooms in same skillet 1 min. Add next 4 ingredients; cook and stir 2 to 3 min. or until Neufchatel is completely melted and sauce just comes to boil. Serve over meat.