Warm the pot: Set a large pot or Dutch oven over medium heat.
Add olive oil and butter. When the butter melts, add the diced onion and a pinch of salt. Cook 4–5 minutes until softened and translucent.
Bloom the garlic and spices: Stir in garlic, Italian seasoning, and red pepper flakes.
Cook 30–60 seconds until fragrant. Don’t let the garlic brown.
Sear the chicken: Add the chicken pieces, season with salt and pepper, and cook 4–6 minutes, stirring occasionally, until no longer pink on the outside. You don’t need a deep sear—just light color.
Add tomatoes and broth: Stir in the chopped sun-dried tomatoes.
Pour in the chicken broth, scraping up any browned bits from the bottom. Bring to a gentle boil, then reduce to a simmer.
Simmer for tenderness: Let it simmer 10–12 minutes, until the chicken is cooked through and flavors meld. Taste and adjust salt and pepper.
Make it creamy: Lower the heat to medium-low.
Stir in the heavy cream and Parmesan until smooth. Keep it at a gentle simmer—do not boil—so the dairy doesn’t separate.
Add greens: Stir in the spinach and cook 1–2 minutes until wilted. If using kale, give it 5–7 minutes to soften.
Finish and brighten: Taste again.
Add a squeeze of lemon if you like a little brightness. Garnish bowls with extra Parmesan and fresh basil.
Serve: Ladle into bowls and enjoy as is, or pair with cauliflower rice or zucchini noodles for extra substance.