1 pound small red potatoes (2½-inch diameter), scrubbed but not peeled
1 pound littleneck clams or other small to medium clams
1 pound mussels
1 pound smoked chorizo, sliced into ½-inch thick rounds
4 lobster tails (6- to 8-ounces each), fresh or frozen
4 large ears corn, husks and silk removed
½ cup melted butter
4 lemons, cut into wedges
Place a steamer basket in a large stockpot. Add 1 inch of water and bring to a boil over high heat. Place potatoes in the basket, cover the pot and steam for 5 minutes.
Place chorizo and lobster tails on top of the potatoes; cover and steam for 5 minutes. Place clams and mussels on top of the lobster tails, and cover and continue steaming for 5 minutes more. Check to make sure there is still 1 inch of boiling water in the pot; if not, add more boiling water.
Place corn on top of the shellfish. Cover and continue steaming until the clams have opened and the potatoes are tender, about 10 minutes more. Check to make sure the clams and mussels are mostly open, the potatoes are tender and the corn is cooked. If not, continue cooking.
Arrange the cooked food on a serving platter. Serve with butter for dipping.