Season the chicken breasts on both sides generously with salt, pepper, and paprika
In a preheated wide pan over medium-high heat, add the oil and when shimmering, sauté the chicken until browned and cooked through (thin-sliced breasts should only take 3 to 5 minutes each side, reaching 165 degrees internal)
Remove the chicken to a separate plate and set aside
Sauté the garlic and tomatoes together until fragrant, about a minute or two
Add the chicken stock and Italian seasoning, stirring to combine with the tomatoes and garlic. Once boiling, add the pasta, reduce to a simmer, and cover. Cook for about 12 minutes until the pasta is done
Once the pasta is finished, stir in the heavy cream and once it's fully incorporated and heated through, add the Parmesan cheese. Stir until the cheese is melted and smooth
Add the spinach and cover. Let it stand for a few minutes until the spinach begins to soften and wilt, 3 to 5 minutes. Mix the spinach into the pasta until it's fully wilted
Slice the chicken breasts on a bias, against the grain, and serve over the pasta
