BBC Food - Recipes - Hot paper bag sandwiches of pastrami, fontina and pickled cucumber

Ingredients

• 150ml/5fl oz rice wine or cider vinegar
• 50g/2oz caster sugar
• 2 tsp sea salt
• 1 tsp yellow mustard seeds
• 1 cucumber , thinly sliced
• 1 small bunch fresh dill , leaves only, roughly chopped
• 12 slices sourdough bread , preferably a mixture of wheat and rye
• 40g/1½oz softened butter
• 1 tbsp Dijon mustard
• 300g/10½oz thinly sliced pastrami
• 400g/14oz fontina, sliced
• vegetable oil , for deep frying
• 3 parsnips , peeled and cut into wafer-thin slices using a potato peeler
• 3 carrots , peeled and cut into wafer-thin slices using a potato peeler
• sea salt and freshly ground black pepper