Chicken and vegetable stew recipe

Name: Chicken and vegetable stew recipe
Prep time: 15 min
Cook time: 50 min
Total time: 1 h 5 min
Cuisine: British
Ingredients: 1 tbsp sunflower oil; 1 onion finely chopped; 4 garlic cloves sliced; 1.4l hot chicken stock; 1 large potato finely grated; 1 tbsp fresh thyme leaf; 2 tsp fresh rosemary leaves; 2 x 850g family packs skinless chicken thighs (count the number in the pack- you need 16 in total); 6 carrots halved lengthways and cut into chunks; 2 parsnips halved lengthways and cut into chunks; 3 leeks well washed and thickly sliced; mash and peas to serve (optional)