1Place potatoes in a saucepan. Add water to cover potatoes; bring to a boil. Reduce heat to medium. Simmer 10 minutes, drain potatoes. Set aside.
2Preheat broiler to high.
3Heat a large Dutch oven over high heat. Add oil to the pan; swirl. Add fish, skin side down; cook 2 minutes or until the skin is crisp. Remove from the pan. Break into 2 inch pieces. (if you don't like the skin, remove it)
4Reduce the heat to medium-high. Add the leak and sliced garlic; saute 5 minutes or until lightly browned, stirring occasionally. Add wine; bring to a boil, scraping the pan to loosen the browned bits. Add 1 cup water and the next 6 ingredients (through bay leaf); bring to a boil.
5Add potatoes, fish, and mussels; cover and cook 4 minutes or until the shells open and the fish is done. Discard any unopened shells, thyme, and bay leaf. Sprinkle with parsley.
6Arrange the bread in a single layer on a baking sheet. Broil 1 1/2 minutes or until toasted. Rub bread generously with the cut-side of the garlic. Serve with the stew.