Any edible mussel will work here, store-bought or gathered. You can also use this recipe with clams, too. The skordalia sauce is great with any fried food, and will keep in the fridge for a week or so.
Make the skordalia first. Dampen the bread with some water, then squeeze it dry. Tear it into pieces and put into a food processor. Add the garlic, salt and pine nuts and pulse a few times. Add the vinegar. Now, with the motor running, slowly pour in the olive oil until you get a mayonnaise-like paste. Set aside.
Pour the white wine into a large, wide pan with a lid. Add the bay leaves and bring to a boil. Add the mussels in one layer and steam with the lid on. As each mussel opens, remove it to a plate. Keep doing this until all the mussels are open.
Remove the mussels from the shells. Remove the wiry beards if they have them; store-bought mussels often don't. Heat enough cheap olive oil in a pot or fryer to be able to deep-fry the mussels. Heat to 350 degrees.
Mix the flour with all the spices and dredge the mussels in it. Shake off the excess and fry in the hot oil until golden, about 2 or 3 minutes. Drain on paper towels. Serve alongside the skordalia.
Note that if you are trying to stay gluten-free, you can use chickpea flour for the mussels, and mashed potato instead of the bread for the skordalia.