How to make
Put about 8 1/3 cups (2 L) of water to boil in a suitable container.
Peel the onion, cut it into pieces and put it in the water, along with the vegetable mix (broccoli, brussels sprouts, peppers, carrots, peas, cauliflowers).
Add the beetroot, peeled and chopped. Boil until the vegetables soften.
To the boiled vegetables, add the butter and salt to taste. After about 5 min., remove the soup from the heat.
Blend it until it becomes homogeneous. Garnish with parsley. When serving, add a spoon of yoghurt if desired.