This is the rich milk a cow gives after she has freshly calved, and apart from its large cream content it also has the properties of eggs, e.g. a teacupful of beestings in a Yorkshire pudding is equal to 2eggs, and it really does rise! Tarts can be made with it as you make custard tarts.
Beestings custard: Add twotablespoonssugar and apinch of salt to 1pint beestings milk in a pie dish. Stir well and sprinkle with a pinch of mixed spice. Cook it in a very slow oven, like an egg custard, until set.