From 1916:
One quart celeriac cut in dice, 2 tablespoons butter, 1 tablespoon flour, 1 teaspoon salt, 1 gill stock or cream.
Cook celeriac 30 minutes in boiling water, rinse in cold water, then press through puree sieve. Put butter in saucepan and on fire. When hot add flour and stir until smooth and frothy, then add strained celeriac and cook five minutes, stirring frequently. Add salt and stock of cream and cook five minutes longer. If puree seems dry, add more stock or cream. The vegetable varies as to amount of moisture it requires. It should be eaten very hot.
If used as a garnish, it is generally put in center of dish and poultry or meat placed on it or around it. Otherwise it may be served on toast or fried bread as a dish by itself.