Sheep's hearts cooked in red wine

This is a nice recipe for lamb's or sheep's hearts. Hearts from an adult sheep will need slightly longer cooking than lamb hearts.

To serve 4.

4 lamb or sheep hearts

Marinade:
100 ml table vinegar
2 sprigs fresh thyme (or 1 tsp dried)
4 garlic cloves, finely chopped
3 laurel leaves
salt and pepper

For cooking:
100 g butter
100 g smoked bacon, finely chopped
10-15 shallots, sliced
1-2 tbsp