Melt 2 tablespoons butter in a large Dutch oven or pot over medium-high heat. Add the onion and garlic and cook, stirring, until slightly softened, about 4 minutes. Stir in the tomato paste, paprika and oregano and cook, stirring, until the mixture begins to brown, about 2 minutes. Add the wine, clam juice and 1 cup water. Bring to a boil and add the potatoes; cook until almost tender, about 8 minutes.
Add the clams to the pot, cover and cook until they begin to open, about 5 minutes. Stir in the kale and the remaining 1 tablespoon butter. Cover and continue cooking until all of the clams open andthe potatoes are tender, 4 to 5 more minutes. (Discard any clams that do not open.)
Divide the clams, kale and potatoes among bowls using a slotted spoon. Top with the broth and sprinkle with paprika. Serve with bread.