Soup for the Soul

Here's a recipe which I adapted from Karen Cheng's blog for wholesome beef soup:

1kg of beef bones, washed
1 oxtail, about 1 - 1.2 kg, washed (or substitute with 300g of tough beef cut, e.g. brisket, plate or flank)
2 large brown onions, peeled and quartered
2 stalks of celery, peeled and cut into medium pieces
2 carrots, peeled and cut into large pieces
2 medium potatoes, peeled and cut into large pieces
2 tomatoes, quartered (optional)
chopped rosemary
2 bay leaves
½ - 1 teaspoon of peppercorn (depending on whether you like it 'pepper-hot')
½ teaspoon salt
1 teaspoon soy sauce (optional)

1) Bring a medium pot of water to boil. Add bones, bay leaves, peppercorn and salt. Boil for at least 1/2 hour.
2) Add oxtail, onions, carrots and potatoes. Simmer on low heat for 2.5 hours.
3) If using tomatoes - Score the tomato skin, blanch in hot water and remove the curled skin
4) Add celery and tomatoes. Continue to simmer on low heat for 30 - 40 minutes.

Taste, add salt and soy sauce for seasoning, if required.