n a blender, prepare the marinade for the anchovies by blitzing 1 clove of garlic with the juice of 1 lemon, the olive oil and white wine vinegar, a few parsley leaves, and a pinch of salt.
Put the anchovies in a baking dish and pour the marinade on top, cover with cling film and leave to rest for at least 5 hours. Meanwhile, slice the old bread and put it on an oven tray lined with baking paper.
Toast the bread in the preheated oven at 200°C for 5 minutes, until golden. Remove from the oven and rub a peeled garlic clove on each slice. Put the slices of bread in a large saucepan, cover them with the tomato purée and pour the vegetable stock on top until they are completely covered. Cook over a gentle heat for 30 minutes, add salt and pepper to taste and stir regularly.
Make the Grana Padano wafers by putting little heaps of the grated cheese on a baking tray lined with baking paper and bake in a preheated oven at 180 °C for 5-6 minutes, until golden. Serve the bread and tomato soup at room temperature, garnished with the marinated anchovies and Grana Padano wafers.