In a big bowl mix soy and sweet chilli sauce. Add the chicken wings and rub them with the sauce. Leave them to marinade in the fridge for night or outside for a few hours. Rinse the wheat, drain it and leave it to soak in cold water, also for a few hours.
Turn on the oven to medium heat. Oil the baking dish with the olive oil. Chop the parsley and the onion and mix it with the crushed tomatoes. Drain the wheat and mix it with the tomatoes also. Season with a little salt and pepper. Spread the wheat in the oiled backing dish and top it with the marinaded chicken wings. Add half of the marinade. Cover with thin foil and put in the oven for an hour.
After an hour uncover the dish, shake it a bit and put it back in the oven for another hour. In the middle of the second hour, turn the wings over so they'll get colour from both sides. Garnish with fresh chopped parsley. Serve hot.