Steam the frozen vegetables with fat, salt, sugar and water until done.
Mix egg yolk, condensed milk, cornflour and 1 tbsp.
breadcrumbs, add to vegetables and boil briefly.
Form small rolls from the vegetable mixture in breadcrumbs, coat all around with breadcrumbs, let cool and bake in hot fat. Arrange the croquettes on a napkin and serve with tomato sauce.