First, make the garlic butter. Blitz all the ingredients in a food processor, then set aside. The butter can be made ahead and chilled in the fridge for up to five days. Toast one side of each sourdough slice under the grill. Spread the other side thickly with the butter and place under the grill again until the butter is bubbling. Turn off the grill and keep the toasts warm.

Heat the oil and butter over a medium heat in a large pan with a lid. Add the parsley stalks, bay leaf, shallot and ½ tsp pepper, and sweat for a few mins until the shallots are softening and fragrant. Add the mussels and white wine, stir, cover tightly with a lid and steam for 2-3 mins until all the mussels have opened.

Spoon into bowls, pour over the pan juices, scatter over some chopped parsley and serve with the toasts.