Chicken Rice with Buttered Onions

Name: Chicken Rice with Buttered Onions
Cook time: 1 h 10 min
Total time: 1 h 10 min
Cuisine: American
Ingredients: 2 to 2 1/4 pounds bone-in, skin-on chicken thighs (4 to 6); Kosher salt and freshly ground black pepper; 1 tablespoon olive oil; 3 tablespoons unsalted butter, divided; 1 1/2 pounds (3 large) yellow onions, diced into just shy of 1/2″ pieces; Leaves stripped from a few sprigs of thyme; 1 1/2 cups uncooked white rice, any variety; 1/4 cup white wine (optional); 2 cups chicken broth and up to 1/4 cup more if needed (updated)