Start by patting chicken breasts dry with paper towels – this helps them brown better. Season generously with salt and pepper on both sides. Cut them in half horizontally if they’re particularly thick to help them cook evenly.
Heat 1 tablespoon each of butter and olive oil in a large skillet over medium-high heat. Once the butter starts bubbling and foaming, add your chicken. Cook for 5-6 minutes on each side until golden brown with a nice crust. You’ll know they’re ready to flip when they release easily from the pan. Transfer to a plate and tent with foil.
In the same pan (don’t clean it – those brown bits are flavor!), add remaining butter and oil. Add your diced onion and cook until it becomes translucent and soft, about 4-5 minutes. Toss in the mushrooms and cook until they release their moisture and start to brown, about 4 minutes.
Add minced garlic and cook for just 30 seconds until fragrant – watch carefully as garlic burns quickly. Stir in dried thyme, rosemary, and oregano, letting them toast for about 30 seconds to wake up their flavors.
Meanwhile, cook your basmati rice. Rinse it well until the water runs clear – this prevents gummy rice. Use 2 cups rice to 3 cups water, bring to a boil, then reduce to lowest heat and cook covered for 15 minutes.
Back to your pan – pour in the chicken broth and scrape up all those browned bits from the bottom. Add heavy cream and bring to a gentle simmer. Don’t let it boil or the cream might separate. Cook until the sauce starts to thicken and coat the back of a spoon, about 5-7 minutes.
Return chicken to the pan and nestle it into the sauce. Add spinach and let it wilt into the sauce. Simmer until chicken is cooked through (internal temp of 165°F) and sauce is nicely thickened, about 5 minutes more.
Finish the sauce with lemon juice, Parmesan cheese, and fresh parsley. The sauce should be silky and coat a spoon – if it’s too thick, thin it with a splash of chicken broth.
Let the dish rest for 5 minutes before serving – this lets the sauce thicken slightly and the flavors meld. Serve the chicken and sauce over the fluffy rice, making sure to spoon plenty of sauce over everything.