Wash the snails and boil them for 15 minutes with a pinch of salt. Wash and drain the greens, the spiny chicory and the endives. Boil them for 5 minutes. Drain them and leave them apart. In a stew pot add the pre boiled snails and boil them with a bit of olive oil together with the onions and the fresh chopped herbs. Add the greens, the spiny chicory and the endives Add salt and pepper. Squeeze the lemons in a bowl. Take half cup out of the boiling water and add the saffron. When the fricassee has cooked and only a small amount of liquid remains in the pot, turn off the heat and add the saffron. In a small bowl, whisk together the egg whites with 1 tablespoon of cold water until frothy. Whisk in the egg yolks and the lemon juice. Add 1-2 ladlesful of liquid from the pot to the egg-lemon mixture and stir gently. Slowly pour the egg-lemon sauce over the snails. With a wooden spoon, stir gently 4 times. Then shake the pot gently side to side to distribute. Allow to sit covered on the stove for 10 minutes before serving.