Bring a large pot of salted water to a boil and cook pasta until just shy of al dente. Reserve 1 cup of pasta water, then drain.

Season the sliced chicken with Cajun seasoning, smoked paprika, salt, and pepper. Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.

Add the chicken in a single layer and sear until golden and cooked through, about 3–4 minutes per side. Remove and set aside.

In the same skillet, add remaining oil or a knob of butter. Sauté the onion until translucent; the butter will bubble and release a warm, toasty scent.

Add garlic and cook until fragrant, about 30 seconds.

Stir in the Cajun seasoning (if you used less on the chicken), then pour in the chicken broth, scraping up any browned bits and let the broth reduce slightly for 2–3 minutes.

Lower heat to medium and stir in the cream. Allow the sauce to come to a gentle simmer; it should thicken and coat the back of a spoon within a few minutes.

Add the Parmesan cheese, stirring until silky. If the sauce becomes too thick, loosen with reserved pasta water a splash at a time.

Return the chicken to the skillet and nestle the pasta into the sauce. Toss gently until everything is glossy and well-coated.

Fold in the spinach and cherry tomatoes just until the greens wilt and the tomatoes warm through.

Taste and adjust seasoning, a squeeze of lemon brightens the richness.

Serve immediately, sprinkled with parsley and extra Parmesan.