Mushroom stifado

Name: Mushroom stifado
Ingredients: 25g dried porcini mushrooms; 100ml olive oil plus extra for drizzling; 500g pickling onions; 1kg mixed mushrooms such as oyster, cep, chestnut, morel, Portobello; 3 garlic cloves finely chopped; 125ml dry red wine; 1 tbsp tomato purée; 4 tbsp red wine vinegar; 2 bay leaves; 5 whole allspice berries; 1 large or 2 small cinnamon sticks; 4 whole cloves; 1 tsp black peppercorns; 2 tomatoes peeled and finely chopped; 75g Kalamata black olive pitted and chopped; 2 tsp Greek clear honey; 3 tbsp chopped flat-leaf parsley; 50g vegetarian kefalotyri/ pecorino grated (optional); Horseradish mash (see 'Goes well with'), to serve