How to Make It:
Heat oven to 200°F. In a large pot, bring 4 quarts salted water to boil.
Add pasta and cook until al dente, about 9 minutes. Drain pasta, reserving cooking water. Set pasta aside.
Return cooking water to boil. Add broccoli; boil until just tender and bright green, about 2 minutes. Plunge immediately into a bowl of ice water. Drain and set aside.
Meanwhile, sprinkle both sides of chicken generously with Cajun seasoning.
In a large skillet, heat oil until shimmering. Arrange chicken in a single layer and sauté, flipping once, until temperature on internal thermometer reaches 155°F, about 5 minutes per side.
Remove from skillet, cover with foil and transfer to the oven to keep warm.
Wipe skillet with a paper towel and return to stove. Over medium-high heat, melt butter and heat until foaming. Stir in garlic; sauté until fragrant, about 30 seconds.
Whisk in wine; bring to simmer. Simmer until sauce has reduced by half, about 2 minutes.
Whisk in cream; simmer until slightly thickened, about 2 minutes. Fold in parmesan cheese. Season with salt and pepper.
Add reserved pasta to skillet and toss gently to coat. Arrange broccoli over pasta; top with chicken and garnish with additional parmesan cheese. Serve immediately.
Notes:
To make your own Cajun Seasoning: Combine 1 tablespoon garlic powder, 1 tablespoon Italian seasoning, 1 tablespoon paprika, 1 tablespoon salt, 1/2 tablespoon black pepper, 1/2 tablespoon cayenne pepper, 1/2 tablespoon dried thyme, and 1/2 tablespoon onion powder.
To get a head start: The pasta can be cooked in advance, refrigerated, and refreshed in hot water just before serving.
The broccoli can be blanched and shocked in ice water in advance; simply store in the refrigerator in cold water. The Cajun seasoning can be made anytime.