To start, cut your sirloin steak into one inch cubes. Add 1 Tablespoon of olive oil to a medium sized skillet over medium high heat. Salt and pepper the steak bites and add them to the pan cooking them until they are golden brown.
Remove the steak and set it aside on a plate. Add the mushrooms and garlic to the pan and saute until tender. Add in the heavy cream, shredded parmesan cheese, Italian seasoning, and salt and pepper. Add the steak back to the pan and allow to heat through and sauce to thicken.
Serve over rice or pasta and garnish with chopped parsley.