Cook the Shell Pasta: Bring a large pot of salted water to a rolling boil. Add the shell pasta and cook until al dente, about 8-10 minutes. Reserve ½ cup of the cooking water, then drain the pasta and set aside.

Sear the Steak Bites: Pat the steak bites dry and season with salt and pepper. Heat olive oil in a skillet over medium-high heat. Add steak bites and sear for 2-3 minutes on each side until golden brown. Remove and keep warm.

Sauté the Garlic: Lower the heat and add butter to the skillet, allowing it to melt. Add minced garlic and sauté for about 1 minute until fragrant, being careful not to brown it.

Create the Alfredo Sauce: Pour in heavy cream and stir to combine. Bring to a gentle simmer, then whisk in Parmesan cheese until melted and creamy.

Adjust Sauce Consistency: If the sauce is too thick, gradually add reserved pasta water until you achieve desired creaminess.

Combine Pasta and Sauce: Add drained shell pasta to the skillet with the Alfredo sauce, tossing gently to coat. Heat together for another minute.

Serve with Steak Bites: Plate the pasta and top with seared steak bites. Drizzle remaining pan juices over the top and garnish with parsley if desired. Serve immediately.