Smoked ham, vegetable and bean soup

This soup came about like most of the soups I've created in the past. I had various small amounts of vegetables that need using up and some left over ham from a Sunday joint.

You can substitute some other sweet vegetable like parsnip or swede for the sweet potato and using courgettes instead of green beans works ok too, just add them with the cannellini beans at the end.

SMOKED HAM, VEGETABLE AND BEAN SOUP
Serves 6

INGREDIENTS:
2 tbsp olive oil
1 medium onion, chopped
1 large leek, chopped
2 medium carrots, chopped
2 sticks celery, chopped
1 large waxy potato, cut in to ½ in (1.5cm) dice
2 ½ pts (1.2lt) chicken stock
5 oz (142g) green beans, cut into ½ in (1.5cm) pieces
10 oz (284g) tomatoes chopped
6 oz (170g) piece cooked smoked ham, diced
1 medium sweet potato, cut into ½ in (1.5cm) dice
salt and pepper to taste
10 oz (300g) tin cannellini beans, drained
basil leaves, shredded

METHOD:
Heat the oil in large pan and gently fry the onions, leek, carrots, celery and potato for 5 minutes.
Add the stock, bring to the boil, cover and simmer for 15 minutes.
Add the green beans, tomatoes, ham and sweet potato, return to the boil then simmer for 10 minutes, until the vegetables are cooked.
Season to taste with salt and pepper.
Add the cannellini beans and cook for a further 5 minutes until heated through.
Pour 1/3rd of the mixture in to a food processor and process until smooth. Return to the remaining soup in the pan and mix gently.
Check the seasoning, heat through and serve garnished with the basil leaves.