Cook noodles as directed on package; rinse, cover, and set aside.
Meanwhile, melt 2 tablespoons butter in a large skillet. Chop mushrooms and onion. Add to melted butter, season with salt, and cook for 6-8 minutes, stirring occasionally. Once done, remove from heat.
Spray a separate skillet with cooking spray and heat over medium. Cut steak into strips and add to hot skillet, cooking 6-7 minutes until browned. Add flour and continuously stir for 2 minutes. Add mushrooms and broth, stirring to combine. Bring to a simmer and continue to stir as mixture thickens. Remove from heat.
In a microwave safe dish, steam green beans in a small amount of water. They should become crisp-tender within 3-4 minutes. Mix with 1 tablespoon butter and a dash of salt; or to taste preference.
Serve beef and mushrooms over noodles, with beans and sliced pears on the side.