Mix the tomato paste with soy sauce, garlic passed through the press, add ginger, pepper and mix well.
Transfer the necks to the marinade and mix well.
Dice the onion and pepper and add to the necks in the marinade, mix and place in the refrigerator for 2 hours.
Cut the potatoes into thin slices and transfer to a baking dish greased with butter.
Add mayonnaise to the potatoes, salt and pepper to taste. Mix well.
On top of the potatoes, lay the necks along with the marinade, bake at 180-200 degrees for 1 hour.
Serve hot. Bon Appetit!!!