Place the steak on a tray, seasoning well with salt and pepper, pressing them into the surface of the steak. Heat a large frying pan over high heat until very hot, then add the olive oil. Place the steak in the pan and reduce the heat to medium. Cook the steak to your liking, adding in the thyme and butter in the last minute, basting the butter over the steak. Remove the steak and thyme from the pan and set aside to rest.
Bring a large pot of salted water to the boil and cook the pasta until al dente.
Return the pan to a low-medium heat and add the extra 2 tablespoons of olive oil. Add the onion and garlic and fry for roughly 3 minutes until softened. Add the stock and cream and bring to a simmer. Simmer for roughly 5 minutes until the sauce is reduced and creamy.
Slice your steak into thin strips. When the pasta is cooked, transfer it to the sauce along with 2 tbsp of the pasta cooking water and any juices collected from the rested steak. Mix well to coat the pasta in the sauce before stirring through the sliced steak, thyme, parsley and extra black pepper. Serve immediately with freshly grated parmesan cheese.
When cooking the pasta, a good trick for al dente is to cook 1 minute less than the packet instructions.
Always bring your beef to room temperature by removing from the fridge 15 minutes before cooking.