- 8 ounces spicy smoked sausage (such as andouille or fresh chorizo), cut into 2-inch pieces
- 1 pound small Yukon gold or new potatoes
- 2 pounds mussels, scrubbed
- 1/2 pound jumbo shrimp (raw), peeled and deveined
- 4 tablespoons unsalted butter (1/2 stick), cut into small pieces
- 1 teaspoon seafood seasoning (such as Old Bay), plus more for serving
- 2 pounds littleneck clams, scrubbed
- 2 tablespoons chopped fresh flat-leaf parsley, for serving
- Preheat oven to 450° F with the racks in the upper and lower thirds.
- Roast the sausage and potatoes on a large rimmed baking sheet on the bottom rack until the sausage is cooked through and the potatoes are nearly tender, 20 to 25 minutes. Add the mussels, shrimp, butter, and 1 teaspoon of the seafood seasoning to the baking sheet and toss to combine. Roast until all the mussels have opened and the shrimp are opaque, 12 to 15 minutes more.
- Meanwhile, roast the clams on a separate large rimmed baking sheet on the top rack until opened, 10 to 15 minutes. (Discard any mussels or clams that do not open after 15 minutes.)
- Toss the clams with the sausage, potatoes, mussels, and shrimp and sprinkle with the parsley. Serve with extra seafood seasoning on the side.