Preheat the oven to 160°C / 320°F or prepare the grill to that temperature.
Cut the meat into slices.
Mix the ingredients of the spice mix and rub it on the meat (both sides).
In a large bowl, mix the onions, garlic and sugar.
"Knead" the onions while mixing the ingredients.
Put a layer of onions on a large, hight casserol, then place the meat on top and finish with a layer of onions on top of the meat.
Mix the vinegar with the wine and pour it over the meat and onions but don't use all of it, you might need less and can always add some when there is need for more while cooking.
Cook in the ovon for 1,5 to 2,5 hours (depending on the meat thickness)
You will know that the meat is ready to be taken out of the oven, when you can easily pull the meat apart with two forks. Then pull apart the entire meat and mix with the onions.
You can eat this i.e. with Kraut Salad (recipe on the blog) and tsaitsiki and fries, or in a bun with tsaitsiki, or with potatoes and steamed vegetables as sides.