Taste-of-Tuscany Beef Stew

Ingredients

• 21 ounces lean stewing beef, cut into small pieces
• salt, to taste
• black pepper, to taste
• 1 large onion, finely chopped
• 3 cloves garlic, minced
• 2 large carrots, chopped into large pieces
• 2 sticks celery, chopped
• 2 tablespoons balsamic vinegar
• 1 1/2 cups beef stock, divided
• 4 large mushrooms, sliced
• 1 (14-ounce) can tomatoes, chopped
• 1 tablespoon tomato paste purée
• dried mixed herbs, to taste
• 2 sprigs fresh thyme
• 1/2 teaspoon onion powder
• 1 (15.5-ounce) can cannellini beans or butter beans
• 1 1/2 tablespoons cornstarch
• water, to taste
• fresh parsley, to taste, chopped, for garnish