Italian pasta soup

The recipe for this wholesome and tasty soup was adapted from Children's healthy & fun cookbook (published by DK).

Ingredients:
75g pasta bows (I had replaced it with small shell pasta)
1 large onion (white)
2 potatoes
2 sticks celery
1 large carrot (scrubbed)
1 tbsp olive oil
1 bay leaf
1 tsp dried oregano
1 litre vegetable stock (I used Maggi concentrated chicken stock 上汤鸡精）
400g tinned chopped tomatoes (I used fresh ripe tomatoes)
Bacon (optional) (I used veg ham)
Parmesan cheese (grated) - optional

Methods:
1. Bring a medium-sized pan of water to the boil and add the pasta. Simmer until the pasta is just tender but not completely cooked. Drain well and set aside.
2. Chop the onion into a small pieces. Peel the potatoes and cut them into bite-sized chunks. Slice the celery and carrot into bite-sized pieces.
3. Heat the olive oil in a large saucepan. Add the onion and fry over a medium heat for 8 mins or until it is softened and golden.
4. Next, add the celery, carrot, potatoes, oregano and bay leaf. Stir well and pour in the stock and chopped tomatoes. Stir again and then bring to the boil.
5. When the soup is bubbling, reduce the heat to low. Half-cover the pan with a lid and simmer the soup for 15 mins or until the potatoes are tender.
6. Remove the lid, add the pasta and stir well. Heat the pasta for 5 mins. Ladle the soup into large bowls and sprinkle with Parmesan cheese.