How to make
Peel and slice the zucchini, carrots and potatoes. Add the celery, add enough water and cook until it softens. Strain them from the liquid and leave it to one side. Mash the vegetables into a fine puree.
Add the liquid back and continue to boil. Add the butter and salt. Stir and cook a little while longer - about 5-6 minutes. If necessary, add more water.
Pour it into a bowl and crush a rusk inside, according to the age of the child.
Serve the soup warm.
