Before you begin spiking the meat, it's good to clean it of any membranes and veins.
Leave the spiked meat to season overnight in the fridge. The next day, transfer it to a deep baking dish. Pour the oil over it.
Add the sliced onions and the remaining marinade. Add 1 cup water, cover with aluminum foil and bake in a preheated 356°F (180 °C) oven.
Bake about 2 hours. Then remove the foil and let it crisp for another 20-30 min. if desired.
Mash the onions from the baking with a little of the broth from the baking and mix with the cream. Serve the resulting sauce separately. You can serve the meat with salad or sauteed vegetables.