This another of Mum’s recipes that she’s pinned together when she couldn’t find the cellotape. It was probably published before mayonnaise in all it’s different varieties was available in the supermarket. If you don’t want to go to the trouble of making the mayonnaise use about a cup of a plain bought one and add the mustard and parsley.
Salad dressings these days are many and varied. You can make them yourself or buy them in the supermarket, but in the 1950s you had no choice but to make it yourself. Mum always had a bottle of homemade mayonnaise in the fridge. Today this recipe seems a bit mundane, especially with the condensed milk, but it’s part of my family history and I’m guessing lots of others as well.