Preheat oven to 400°F.
Brush olive oil all over the chicken thighs. Liberally season the chicken with salt and pepper.
Heat the butter in a large oven-safe skillet over medium heat.
Add the chicken, skin side down, and sear for 10 minutes, or until the skins are golden and crispy. Flip the thighs over and cook for another 3 minutes. Remove the chicken from the skillet onto a platter. Discard all, but 2 tbsp, of butter/grease from the pan.
Return the pan to the stove over medium heat. Add the shallots and sauté for about 3 to 4 minutes, or until soft. Add the garlic and sauté for another 30 seconds to 1 minute.
Add the wine and cook until almost completely evaporated, about 2 minutes. Stir in the chicken stock and bring to a simmer. Add the spinach and simmer until completely wilted, about 1 to 2 minutes.
Stir in the basil, parsley, 1 tsp salt, and ½ tsp pepper. Simmer for a few minutes.
Stir in the tomatoes and beans. Nestle the chicken into the sauce, skin-side up.
Place in the oven and bake until the internal temperature of the chicken reaches 165°F, usually about 15 minutes. Remove from the oven and serve at once, garnishing with extra chopped parsley (if desired).
