Well, I have never cooked freshwater mussels but I gave it a try this past week while we were in Alabama. The boys waded into the water with Gene and came out with a sackful. Here is what I did with them.
Freshwater Mussels Steamed in Wine Broth
1 large onion
2 tablespoons olive oil
4 cloves minced garlic
1 teaspoon dried thyme
2 cups chicken broth
2 cups white wine
salt and pepper to taste
30 Mussels cleaned and scrubbed well. Only use ones that are tighly closed or will close when tapping on them.
Saute the onions in olive oil until translucent in a large pot. Add the garlic being careful not to burn. Add the thyme and stir. Then add the chicken broth and wine. Bring to a boil and boil for about 5 minutes. Add the lemon juice and adjust the salt and pepper. Add the mussels, stir and cover. Cook for 4 to 5 minutes. Check and remove any mussels that have opened. Don't over cook. Continue to take them out and place them in a serving bowl as they open. Once all the mussels are cooked pour some of the sauce over them and serve with bread for dipping in the sauce.
--You could really use just about any herbs that you have available
--I think a slosh of heavy cream would be nice in the sauce, after the mussels are removed but before you pour it into the bowl.