Slice the steak into bite-sized pieces, transfer to a large bowl and coat all over in the pepper steak seasoning.
Heat the butter in a large pan over a high heat, once sizzling, sear the steak for 3-4 minutes over, until brown all over and beginning to caramelise, then transfer the steak and garlic to a plate or bowl and set aside.
In the same pan, sauté the onion and pepper for 3-4 minutes over a medium heat, until soft, add the stock, cream, cream cheese, stir to combine and bring the sauce to a gentle simmer. Stir in the steak bites and leave to simmer over a medium heat.
Bring a large saucepan of salted water to the boil, cook the rigatoni for 6-7 minutes, until very al dente. When draining the pasta, reserve a bowl or jug of pasta water.
Whilst the pasta is cooking, stir in the spinach, add a ladle of pasta water and cook the spinach until wilted, then stir in the parmesan. Add the cooked pasta to the pan and toss to combine. Serve immediately and garnish with a little grated parmesan.
