Slow Cooker Stifado

1kg Sliced onion
1kg braising beef cut in cubes
3 garlic cloves, crushed
400 g can chopped tomatoes (use fresh tomatoes if you prefer)
200 ml red wine
30 ml red wine vinegar or 30 ml balsamic vinegar
1tbs tomato paste
2 bay leaves
1tsp ground cinnamon
1tsp ground cloves
pinch dried oregano
splash of brandy
salt and pepper

Cook on low for about 8 hours.