Trim the beetroot and add to a saucepan then cover with water and bring to the boil. Simmer 30 minutes or until tender. Drain and cover with cold water to cool them. Peel and slice the beetroot.
Fill a saucepan with 4 litres water and add the sliced beetroot along with the onions, garlic, drained mushrooms, allspice, bay leaves, salt and pepper. Stir in the oil and lemon juice. Simmer 30 minutes.
Strain off the broth and serve in bowls, garnished with parsley to serve.