Step 1: Bring a large pot of salted water to a boil. Add the pasta shells and cook until al dente. Reserve ½ cup of the pasta water, then drain and set aside.

Step 2: In a saucepan, melt 2 tbsp butter over medium heat. Add half the garlic and sauté for 30 seconds until fragrant. Pour in the heavy cream and milk, whisking until smooth.

Step 3: Reduce the heat and stir in the cheddar and Parmesan until melted into a thick sauce. Season with Italian seasoning, salt, black pepper, and red pepper flakes if desired. Toss in the cooked shells, adding a splash of pasta water if the sauce feels too thick.

Step 4: Pat the steak cubes dry with paper towels. Season generously with Cajun seasoning, smoked paprika, salt, and black pepper.

Step 5: Heat olive oil in a cast-iron skillet over medium-high heat. Sear the steak tips in a single layer for 2–3 minutes on each side until browned and cooked to your preference.

Step 6: Lower the heat slightly, add 3 tbsp butter, and the remaining garlic. Baste the steak tips with the melted garlic butter for 1–2 minutes, spooning it over the meat as they finish cooking.

Step 7: Serve by plating the cheesy shells on one side and the garlic butter steak tips on the other. Drizzle extra garlic butter over the steak and garnish with parsley.