8oz. small waxy potatoes (such as baby Yukon Gold), scrubbed, sliced ¼” thick
½medium fennel bulb, finely chopped
2garlic cloves, finely chopped
Kosher salt and freshly ground black pepper
¼cupdry white wine
1½poundskinless flounder or fluke fillet, cut into 2” pieces
2tablespoonschopped fresh dill
Lemon wedges (for serving)
Heat oil in a large pot over medium-high heat. Cook potatoes, tossing occasionally, until beginning to soften, about 3 minutes. Add fennel and garlic; season with salt and pepper and cook, stirring occasionally, until fennel is soft, about 2 minutes. Add wine, bring to a boil, and cook until almost completely evaporated, about 4 minutes.
Add 2 cups water to pot and bring to a boil. Reduce heat and simmer until potatoes are tender, 10–12 minutes. Stir in crème fraîche. Add flounder, cover pot, and reduce heat. Simmer until fish is cooked through, about 4 minutes.
Stir dill into stew; season with salt and pepper. Serve with lemon wedges.