French Onion Sheet Pan Chicken

Bahan-bahan (6 porsi)

• ⅓ cup beef stock or beef broth
• 2 teaspoons Worcestershire sauce
• 1 tablespoon Kosher salt
• 2 teaspoons freshly ground black pepper
• 2 teaspoons smoked paprika
• 3½ pounds bone-in, skin-on chicken thighs
• 3 tablespoons extra virgin olive oil ((plus more for brushing))
• 2 tablespoons unsalted butter
• 2 large (about 1½ pounds) sweet onions, (thinly sliced)
• 1 teaspoon granulated white sugar
• 3 sprigs thyme ((leaves only))
• ⅓ cup dry sherry, dry vermouth or white wine
• 2 tablespoons finely chopped fresh flat-leaf parsley ((plus more for garnish))
• 4 medium garlic cloves, (minced)
• 6 ounces shredded Gruyere cheese