The lard needs to be soft but not runny. Beat the softened lard with the powdered sugar and vanillas with the mixer on low to mix the ingredients well and obtain a white, creamy mixture. Grind the walnuts finely.
Add them to the lard, sugar and vanilla mixture, now stirring with a spatula or spoon. Add white flour in lots, as needed to obtain a dough. Form it into a ball.
Cover with plastic wrap and leave in the fridge for 20 min. Then make small balls from the dough, flatten them slightly and arrange in a tray. Place a piece of walnut on top in the middle. Carefully press the walnut into the dough.
Bake the macaroons in a preheated 338°F (170 °C) oven about 15 min., until ready.