To begin, dice the sirloin steak into one-inch cubes. Place 1 tablespoon of olive oil in a medium-sized skillet set over medium-high heat. Season the steak bites with salt and pepper, then place them in the skillet, cooking until they achieve a golden brown hue.

Transfer the steak to a plate and set it aside. Introduce the mushrooms and garlic into the skillet, sautéing them until they become tender.

Incorporate the heavy cream, shredded parmesan cheese, Italian seasoning, as well as additional salt and pepper. Reintroduce the steak to the skillet, allowing it to warm through and the sauce to thicken.

Serve this dish over rice or pasta, and enhance it with a sprinkle of chopped parsley.