Roughly chop the celery, onion, and fennel, then toss in a large saucepan and fry in olive oil until they start to soften. Add the minced garlic, stir through, then pour in the white wine and boil.
Once the wine has boiled sprinkle in the Vegeta, add the water and simmer for 40-45 minutes.
Once the soup has cooked blend until completely smooth (sometimes with celery there can be “stringy” bits left over, if so strain the whole soup.)
Bring the soup to a simmer and thicken with the wetted arrowroot if required.
Serve with chopped grissini, as croutons. and garnish with fennel fronds.