Bring a large pot of salted water to a boil. Cook linguine until al dente (usually 9–11 minutes). Reserve 1/2–1 cup pasta water, then drain and set pasta aside.

Pat steak strips dry and season with 1 tsp Cajun seasoning, salt, and pepper.

Heat a large skillet over medium-high heat with 1 tbsp olive oil.

Add steak in a single layer (work in batches if needed) and sear 2–3 minutes per side for medium-rare to medium, until browned. Total searing time ~4–6 minutes. Remove steak to a plate and tent with foil to rest for 5 minutes.

In the same skillet, reduce heat to medium and add 2 tbsp butter.

Add minced garlic and cook 30–45 seconds until fragrant — don’t let it brown.

Optional: If using, pour in 1/2 cup white wine to deglaze the pan, scraping up browned bits for 1 minute. Let the wine reduce slightly.

Pour in heavy cream and bring to a gentle simmer. Simmer 2–3 minutes until the sauce begins to thicken.

Stir in grated Parmesan gradually until melted and smooth. If sauce is too thick, loosen with a splash of reserved pasta water until you reach a silky consistency. Add lemon juice if using.

Add cooked linguine and remaining 2 tbsp butter to the sauce. Toss to coat evenly; simmer 1–2 minutes so pasta absorbs the sauce.

Return steak to the skillet and toss just to combine (1 minute). Taste and adjust seasoning with salt, pepper, and more Cajun seasoning if desired.

Serve immediately, garnished with chopped parsley and extra Parmesan.