Prepare the Steak
Season both sides of the steak generously with salt, pepper, and chopped rosemary.
Heat olive oil in a skillet over medium-high heat. Add the steak and sear for 3-4 minutes per side for medium-rare, or until desired doneness.
Add butter and minced garlic during the last minute of cooking, spooning the melted butter over the steak for extra flavor.
Remove the steak from the pan and let it rest for 5 minutes before slicing thinly against the grain.

Cook the Pasta
Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente.
Reserve ½ cup of pasta water before draining.

Make the Creamy Sauce
In the same skillet used for the steak, add a little more olive oil if needed. Sauté garlic until fragrant (about 30 seconds).
Pour in the heavy cream, stirring to deglaze the pan and incorporate all the flavorful bits from the steak.
Stir in the Parmesan cheese, allowing it to melt and thicken the sauce. Add reserved pasta water gradually until you achieve your desired sauce consistency.
Toss in cherry tomatoes and spinach (if using), cooking until the spinach wilts and tomatoes soften.

Combine and Serve
Add the cooked pasta to the sauce, tossing to coat evenly.
Top with the sliced steak and gently mix or serve the steak on top for presentation.
Garnish with fresh parsley and additional Parmesan if desired. Serve warm and enjoy!