Set a large heavy pot over medium high heat, and add the lardons. Fry until crispy.
While the bacon is frying, slice the corn kernels from the cobs and set aside.
Start a small pot of water to boil and add the cut potatoes. Simmer until just tender. Drain and set aside.
When the bacon is crispy, add the shallots, onion, serrano and paprika. Cook until the onion is soft. Add the corn, zucchini and tomatoes. Cover the pot with a lid, reduce the heat to medium-low, and allow to simmer for a couple of minutes. The tomatoes should be soft and the corn still al dente.
Stir in the juice from the lime, and the Rum. Cook for an additional minute. Remove from the heat and cover with a lid to keep warm while you prepare the seafood.
Place the clams in a pot with 1/4 cup of water over medium - high heat, covered with a lid. Cook the clams until the shells have all opened, about 10 minutes, and discard any that do not open. Add the clams to the corn stew.
Lightly salt and pepper the shrimp. Place a sauté pan over medium - high heat, add the olive oil. When hot, add the shrimp and sauté for 2 minutes, then flip and cook for another minute. Add to the corn stew.
Serve with garlic bread and a salad. It's great warm or at room temperature.