Tuscan-Style Chicken, Bean and Tomato Soup

Ingredients

• 1 tbsp olive oil
• 1 onion (chopped)
• 1 carrot (chopped)
• 2 celery stalks (chopped)
• 1 zucchini (chopped)
• 410 g four-bean mix (rinsed and drained)
• 300 g chicken thighs (boneless, skinless, trimmed and sliced)
• 4 cups chicken stock
• 1 bay leaf
• 1 tsp dried oregano
• 1 lemon grated zest (optional)
• 150 g baby spinach leaves (chopped)