Break the eggs, add the yoghurt and stir. Add the softened lard, oil, sugar, baking soda and lemon zest.
Stir and add the flour in lots until you've kneaded a soft dough. If it's not enough, add a little more.
Tear balls from the dough and shape the cookies.
Dip each in sugar and arrange them in a tray laid out with baking paper, with the sugary side facing up.
Bake in a preheated 392°F (200 °C) oven until reddened.