Beat the sugar, orange juice and oil in a bowl with a mixer. Add the ground almonds and lemon juice, in which you've dissolved 1 tsp of hartshorn ahead of time.
Roll it out out into a sheet and cut out cookies of the desired shape. Arrange them in an oiled tray or on top of baking paper. Put them to bake to a nice crisp in a preheated 356°F (180°C) oven.