Pat chicken pieces dry with paper towels and season generously with salt, pepper, and paprika. Heat olive oil in a large skillet over medium-high heat until shimmering, then carefully add chicken in a single layer and let it sear undisturbed for 3-4 minutes until golden.

Flip each piece and cook the other side for another 3-4 minutes until the internal temperature reaches 165°F. Transfer cooked chicken to a clean plate and set aside while you build the aromatic base.

Reduce heat to medium and add butter to the same skillet, then sauté diced onions for 2 minutes until they begin softening. Add minced garlic and sliced mushrooms, stirring frequently for 4 minutes until the mushrooms release their moisture and begin browning.

Pour chicken broth into the pan, scraping up all those flavorful brown bits stuck to the bottom using a wooden spoon. Bring the mixture to a gentle simmer and let it reduce for 2 minutes before stirring in heavy cream, dried thyme, and returning the sizzling creamy chicken skillet ingredients to the pot.

Nestle chicken pieces back into the sauce and let everything simmer together for 3-4 minutes until the sauce thickens slightly and coats a spoon. Stir in fresh spinach and grated parmesan cheese until the spinach wilts completely and the cheese melts into the creamy sauce.

Taste and adjust seasonings with additional salt and pepper if needed, then finish with fresh chopped parsley for bright color and herbaceous freshness. Serve immediately while the sauce is still luxuriously creamy and the flavors are at their peak.