Salmon & asparagus one-pot gratin - Master recipes

Ingredients

• 30g dried breadcrumbs -
• 2 sprigs parsley, leaves picked and chopped -
• 100g parmesan -
• 1 tsp olive oil -
• 25g unsalted butter -
• 1 red onion, finely chopped -
• 1 garlic clove, crushed or finely grated -
• 300ml double cream -
• 100ml milk -
• 500g asparagus, trimmed and halved -
• 4 skinless salmon fillets -