Preheat your oven to 425°F. Toss the cauliflower florets with a pinch of salt, pepper, and a drizzle of olive oil if desired, then spread them on a baking sheet.
Roast the cauliflower in the preheated oven for 20-25 minutes, stirring halfway through, until they are golden and tender.
While the cauliflower roasts, season the steak generously with salt and pepper on both sides.
Heat a skillet over medium-high heat. Once the pan is hot, add the steak and sear for about 3-4 minutes per side for medium-rare, or adjust cook time according to your liking.
Remove the steak from the skillet and let it rest on a cutting board for a few minutes.
In the same skillet, reduce heat to medium-low and add the unsalted butter. Add the minced garlic and sauté for about 30 seconds until fragrant.
Pour in the heavy cream, stirring continuously to combine with the garlic butter, creating a light creamy sauce.
Slice the steak against the grain, drizzle the garlic butter cream sauce over the slices, and sprinkle with fresh parsley.
Plate the steak with a generous side of roasted cauliflower and enjoy hot.