Wash and dry the herbs with absorbent paper. Peel the onions and cut into slices. Crush the pepper. At the bottom of a pan accommodate a sprig of thyme, a couple of onions, a bay leaf and sprinkle with a little pepper and salt. Place a layer of sardines on top, season with salt and pepper, add another layer and so on until finished. Dip with vinegar and oil. Sardines should be covered. Sprinkle with another little salt and keep covered in a cool place or in a refrigerator one day before eating. To drain the oil, remove the sardines and place them on a tray or directly on the plates. Surround with curly escarole only seasoned with salt and oil.