Mussels with Roasted Potatoes

Preparation

1. Step 1

   Preheat oven to 450°F.

   Step 2

   Halve potatoes lengthwise and trim a 1/4-inch-thick slice from side opposite cut side of each potato half to form 8 flat slabs (1/2 to 3/4 inch thick). Discard trimmings, then coat potato slabs with 2 tablespoons oil and sprinkle with all of salt. Arrange in 1 layer in a large shallow baking pan (1 inch deep) and roast in middle of oven, turning over once halfway through roasting, until golden brown and tender, 25 to 30 minutes total.

   Step 3

   Shortly before potatoes are done, cook shallot, garlic, and red pepper flakes in 2 tablespoons oil in a deep 12-inch heavy skillet over moderate heat, stirring, until softened, about 3 minutes. Add wine and water and bring to a simmer. Add mussels and cook, covered, over moderately high heat until they just open wide, checking frequently after 3 minutes and transferring opened mussels to a bowl. Discard any mussels that remain unopened after 6 minutes.

   Step 4

   Whisk parsley and remaining 2 tablespoons oil into mussel broth and season with salt and pepper.

   Step 5

   Divide potatoes among 4 shallow bowls and top with mussels and broth.