BBC Food - Recipes - Crab and scallop Mornay

Ingredients

• 6 large diver-caught scallops , shucked (keep the shells)
• knob of butter
• 100g/3½oz white or brown (or a mixture) handpicked crab meat
• 500ml/18fl oz whole milk
• 1 bay leaf
• ½ small onion , finely sliced
• 30g/1oz butter , plus extra for greasing
• 30g/1oz plain flour
• 1½ tsp English mustard powder
• 3 tbsp white wine
• 2 tbsp single cream
• 25g/1oz Gruyère cheese, finely grated
• 2 heaped tbsp snipped chives
• 25g/1oz white breadcrumbs , made with crust-less day-old bread
• 3 heaped tbsp finely chopped curly parsley (optional)
• flaked sea salt and freshly ground black pepper