Moules with Watercress Butter and Toasted Sourdough - James Martin Chef

Ingredients

• 1 bunch watercress
• 150g softened butter
• 50g butter
• 1 onion peeled and diced
• 2 sticks celery diced
• 1 leek diced
• 2 cloves garlic, peeled and crushed to a paste
• 2 k mussels cleaned
• 250ml white wine
• 250ml double cream
• 4 Thick slices of white crusty bread
• 2 tbsp olive oil
• 1 Small bunch of parsley
• 4 slices toasted sourdough