1. Steam the mussels and the clams by placing them into 2 separate saucepans; add 1 tbsp. of oil and ½ cup of white wine in each of the pans and bring to a boil, add the mussels into one pan and the clams into the other, cover with a lid and cook until they are all open, shake the pans occasionally to move the molluscs and allow them to open better.
2. Remove from the heat and once cooled enough remove all the shells, keep the meat and the juices separate for use in the recipe.
3. Preheat a saucepan at medium/hi heat, add the butter and the oil, once the butter is melted add the shallots and the garlic and cook until translucent.
4. Add the flour and stir well to dissolve all the lumps. Add the wine and evaporate a bit to remove the alcohol.
5. Then and the juice of the clams and mussels then add the cream and cook until dense enough to coat the back a spoon. At this point add the shrimps and the scallops and cook for no longer then a minute, add the rest of the cooked seafood (clams, mussels, crab & lobster) season with salt and pepper as needed, then add the fresh herbs and fill the vol-au- vent just before serving them.
6. Preheat the vol-au- vent just before filling them for a fresher taste.

One great variation to this recipe is:

Add 1 cup of shredded gruyere cheese along with the fresh herbs, fill the vol-au- vent and top with more cheese then place under the broiler until golden, serve immediately. Sometimes in stores will have pre-baked as well as frozen Vol-au- Vent and you might find only small size, so my recommendation is to give two or three per guest, you will use the same amount of seafood anyway. Sometimes you might have to ask the store to procure the vol-au- vent well in advance