Prepare the chicken: Season the chicken breasts generously with salt and black pepper on both sides. Let them sit at room temperature for ten minutes — this helps them cook more evenly.

Brown the chicken: Heat the olive oil in a large frying pan over a medium-high flame until it shimmers and smells fragrant. Lay the chicken in the pan in a single layer — you should hear a satisfying sizzle. Cook for 5 minutes until the underside is a deep golden brown with a crisp crust, then flip and cook for another 4 minutes. The chicken should feel firm to the touch. Transfer to a plate and set aside.

Sweat the aromatics: Reduce the heat to medium. Add the diced onion to the pan and stir, scraping up any browned bits from the bottom. Cook for 3 minutes until the onion turns translucent and softens. Add the sliced garlic and sun-dried tomatoes, stirring for another minute until the garlic releases its sweet, aromatic scent.

Build the sauce: Pour in the chicken stock and let it bubble for 2 minutes, reducing slightly. The liquid will take on a warm, tomatoey hue. Lower the heat and stir in the double cream, grated Parmesan, oregano, and thyme. Watch as the sauce thickens to a silky, pale orange consistency — it should coat the back of a spoon.

Wilt the spinach: Add the fresh spinach to the pan in handfuls. Stir gently as the leaves collapse into the sauce, turning a vibrant emerald green. This takes barely a minute.

Finish the dish: Return the browned chicken breasts to the pan, nestling them into the creamy sauce. Spoon some sauce over the tops. Let everything simmer together on low heat for 8-10 minutes, until the chicken is cooked through and the sauce has thickened to your liking. The kitchen will smell absolutely incredible at this point.

Rest and serve: Remove the pan from the heat and let it sit for 5 minutes. This rest time allows the juices in the chicken to settle. Garnish with fresh basil leaves if you like, then serve straight from the skillet.