Bring a large pot of salted water to a boil and cook pasta according to package directions until al dente. Reserve 1 cup of pasta water, then drain the pasta.

Season the chicken slices generously with salt, pepper, and half the smoked paprika.

Heat olive oil in a large skillet over medium-high heat until shimmering. Add the chicken in a single layer and sear until golden, about 3 minutes per side. Remove chicken and set aside.

Reduce heat to medium, add butter to the pan and let it melt. The butter will bubble and release a nutty aroma — that’s when you add the garlic. Sauté for about 30 seconds until fragrant.

Stir in the remaining smoked paprika and red pepper flakes, then pour in the chicken broth or wine to deglaze the pan, scraping up the browned bits. Let it simmer and reduce by half, about 2 minutes.

Pour in the heavy cream and bring to a gentle simmer. Add lemon zest and juice, Parmesan, and stir until the sauce thickens slightly. Taste and adjust salt and pepper.

Return the chicken to the skillet along with any juices, then add the drained pasta and toss to coat. If the sauce seems thick, add reserved pasta water a little at a time until you get a silky consistency. Fold in spinach or tomatoes if using.

Finish with chopped parsley and chives, and a generous grating of Parmesan. Serve immediately, with extra lemon wedges at the table.