Heat the skillet over medium heat and add the butter until melted.
Season the chicken thighs with salt and pepper, then add them to the skillet, skin side down.
Flip the chicken thighs and add onions and garlic to the pan. Sauté until onions are soft and translucent.
Pour in the chicken broth, lemon juice, and zest, then nestle the rice around the chicken.
Reduce heat to low, cover, and simmer for about 20 minutes until rice is cooked and chicken is tender.
Stir in the heavy cream, letting it meld into the flavors, and adjust seasoning.