Cook the pasta: Bring a large pot of salted water to a boil. Cook pasta until just shy of al dente.
Reserve 1/2 cup pasta water, then drain.
Sauté aromatics: Heat olive oil in a large skillet over medium. Add onion with a pinch of salt and cook 3–4 minutes until translucent. Stir in garlic and cook 30 seconds until fragrant.
Brown the chicken: Add ground chicken, season with salt and pepper, and break it up with a spoon.
Cook 5–7 minutes until fully cooked with light browning. Don’t overcrowd; let it sear for flavor.
Season the base: Sprinkle in Italian seasoning, red pepper flakes, and smoked paprika. Stir to coat the chicken and bloom the spices for 30–60 seconds.
Add tomatoes and broth: Stir in crushed tomatoes, tomato paste, and chicken broth.
Simmer 5–7 minutes until slightly thickened.
Make it creamy: Reduce heat to low. Stir in cream or Greek yogurt. If using yogurt, temper it by mixing with a spoonful of warm sauce first to prevent curdling.
Add Parmesan and mix until smooth.
Add greens: Fold in spinach and let it wilt, 1–2 minutes. Taste and adjust salt and pepper. Add a squeeze of lemon if you like brightness.
Combine with pasta: Add drained pasta to the skillet.
Toss, adding splashes of reserved pasta water as needed to loosen and help the sauce cling.
Finish and serve: Top with more Parmesan and chopped basil or parsley. Serve hot.