Rosella tomato soup arrived on the scene in July 1921: "ROSELLA TOMATO SOUP. Made from choicest tomatoes, delicately flavoured. It is highly concentrated, and therefore economical."
Rosella tomato soup tastes very similar to soup made to 1920s recipes, and the instructions on Rosella soup cans still suggest diluting with half water, half milk or all milk. This recipe published in the Argus on 4 January 1922 is not dissimilar to Rosella Tomato Soup, but it's fresher and lighter.
In a large saucepan, melt 1 tblsp butter, add the flour, cook for a minute or two, then add the milk, stirring vigorously to get rid of any lumps. When the sauce is smooth, season with salt and pepper.
In another saucepan, put the tomatoes, 1 tblsp butter, the sugar, mace, water, onion, a little salt and pepper and the herbs, if any. Cook until the tomatoes are quite soft, then pass the whole through a sieve and add it to the white sauce. If too thick, a little water may be added. Bring to a simmer and serve with fingers of buttered toast or croutons (dice of bread, fried).
The soup only took 15 minutes to make. I used fresh parsley and oregano but no mace.