Start by gathering all your ingredients. Cut your sirloin steak into bite-sized pieces, then season them generously with salt and pepper. Mince the garlic and measure out the other ingredients to ensure a smooth cooking process.

Heat the olive oil in a large skillet over medium-high heat. Once it’s shimmering, add the seasoned steak bites in a single layer. Sear them for about 2-3 minutes on each side until they reach your desired level of doneness. Transfer them to a plate and set aside.

Lower the heat to medium and add the butter to the skillet, letting it melt completely. Stir in the minced garlic, cooking it for about 1-2 minutes until fragrant.

Pour in the heavy cream while stirring constantly, bringing the mixture to a gentle simmer, and then gradually whisk in the grated Parmesan cheese until completely melted.

Mix in the Italian seasoning and taste to adjust any additional salt or pepper.

In a separate pot, bring water to a boil and cook the shell pasta according to the package instructions until al dente, usually about 8-10 minutes. Drain and set aside.

Add the drained shell pasta into the skillet with the Alfredo sauce, tossing gently to coat.

Fold in the cooked steak bites and heat everything through for another 2 minutes.

Serve in bowls and garnish with chopped parsley.