Bring a pot of salted water to a boil. Cook pasta 1 minute less than the packet instructions. Drain and reserve roughly ½ cup of pasta water.
Slice the steak into thin strips and place it in a bowl. Season with salt and pepper to your liking.
Place a large, high-rimmed pan over high heat. Add olive or avocado oil and sear the steak in batches for 2 minutes on each side or until golden. Remove and set aside.
In the same pan, back over medium-high heat, add unsalted butter and allow it to melt. Add the grated garlic and sauté for 1 minute. Deglaze with stock and cook for 1 minute. Add unsweetened evaporated milk or cream, smoked paprika, chilli powder or flakes, salt, and pepper. Mix to combine, bring to a simmer, reduce the heat to low, and cook for 5-6 minutes or until reduced.
Add the baby spinach and cooked pasta and cook for 1 minute, or until the baby spinach has wilted and the pasta is coated in the sauce. Add the cooked steak and resting juices. Mix to combine and remove from heat.
Serve in 6-7 meal prep containers. Garnish with flat-leaf parsley and parmigiana reggiano.