Onion Soup in the Umbrian way

Preparation:

Preparation: Peel the onions, cut them into thin slices and soak them in a bowl full of cold water for half a day. After this time, finely chop the lard, using the mezzaluna, place the resulting mixture in a saucepan together with the olive oil and brown gently for a couple of minutes. Then add the onions, well drained, and let them infuse without letting them brown. Also add the coarsely chopped basil, sprinkle with a pinch of salt and a grind of pepper, close the container and cook over moderate heat for about ten minutes. Put the sieved tomatoes in the saucepan, wet the preparation with a scant liter of water and cook for another hour and a half, stirring occasionally with a wooden spoon. At the end, remove the saucepan from the heat, add two beaten eggs and the grated Parmesan to the onions, stir to mix everything well, finally transfer the preparation into a hot bowl. Serve immediately, accompanying the soup with slices of homemade bread toasted in the oven.