Mussel Brose

Name: Mussel Brose
Cuisine: British
Ingredients: Freshly ground sea salt, black pepper, chopped chives and parsley, to finish; 1 heaped tbsp chopped parsley; 1 medium onion, finely chopped; 500 g potatoes, weighed when peeled and diced. Choose a floury variety that is good for mash; 200 ml dry white wine; Wash and de-beard 1 kg mussels. Discard any that are cracked or open; 100 ml water; 50 g slightly salted butter; Freshly ground black pepper; Approximately 250 ml fresh milk plus 150ml double cream; 2 rounded tbsp medium oatmeal; 200 g onion, weighed when peeled and chopped quite small; 2 large cloves garlic, finely chopped