Grilled Pork Kidneys

Preparation and cooking time:
about 10 minutes, plus the time needed for salting and hanging.

Ingredients for 4 people:
4 pork kidneys
vegetable oil
1 branch rosemary
1 garlic clove
white vinegar
a few sage leaves

Cut the kidneys in half lengthwise using a very sharp knife; carefully remove all the fatty parts. Holding one end, dip them into boiling water just once; place them in one layer in a colander and salt generously with table salt. Let them rest for about one hour, to drain them of their blood.
Meanwhile, wash the rosemary and sage leaves and mince them together with the garlic. Wash the kidneys thoroughly and dry them with a clean cloth; arrange them on a large plate, sprinkle with the minced herbs and garlic, drizzle with half a cup of oil, and sprinkle over two tablespoonfuls of vinegar. Turn them over to season them on both sides; let them rest in a cool place for another two or more hours, as desired. Wipe the herbs and garlic off the kidneys and cook them on both sides on a very hot grill, at high heat, basting them occasionally with a little oil (not from the marinade). When done, salt and pepper them and arrange them on a heated platter, with lemon slices. Serve the kidneys hot with French fries or a green salad.