In a medium bowl combine the lemon zest, paprika, Piment d'Espelette chilli pepper, garlic, 3/4 teaspoon salt, and 3/4 teaspoon pepper. Add the shrimp and toss to coat.
In a large pot, melt butter over medium-high heat. Add the shrimp and cook, stirring and turning the shrimp for about 2-3 minutes. Transfer the shrimp to a plate with a slotted spoon. Set aside.
Turn the heat down to medium, add the leeks, season with salt and pepper. Cook for about 4-5 minutes or until the leeks are soft and just starting to brown on the edges.
Add the beans and chicken broth and bring to a boil over high heat. Lower the heat and simmer for about 8 minutes. Stir in the reserved shrimp and any juices on the plate, the parsley, lemon juice, and season with salt and pepper. Serve with sliced Ciabatta bread.