Heat oil in large saute pan over medium high heat.
Add peppers onions and mushrooms to the pan and saute to soften, around 5 minutes.
Add beef and season with salt, pepper and garlic powder. Saute for 2-3 minutes to begin browning.
While beef begins to brown, whisk together corn starch, broth, heavy cream and Worcestershire sauce until well combined. Pour into the pan and mix well.
Add pasta to the pan and bring to a boil.
Cover and reduce heat to medium. Simmer for 15 minutes stirring periodically.
Remove cover and stir in ½ cup of cheese.
Sprinkle the remaining cheese on top and cover and cook for 5 more minutes to melt the cheese. Serve immediately.