Chicken in Vinegar

Name: Chicken in Vinegar
Ingredients: 1 whole chicken (3 1/2 pounds/1.6 kg), cut into 8 pieces; Salt and freshly ground pepper; 1 tablespoon butter, plus another tablespoon for finishing; 1 tablespoon olive oil; 6 cloves garlic, peeled; 1 cup/250 ml white wine vinegar; 1 cup/250 ml chicken stock; 1 tablespoon tomato paste; 4 medium tomatoes, roughly chopped; 1 bay leaf; 1 large fresh thyme sprig; 2 good handfuls chopped fresh parsley