Step 1Heat the oven to 350 degrees. Cook the chorizo in olive oil in the bottom of a Dutch oven over medium heat on the stove top until the chorizo has rendered some fat and begun to brown, about 5 minutes. Add the bell pepper and cook until it begins to soften, about 3 minutes. Add the onion and cook until soft, about 5 minutes. Add the garlic and cook until fragrant, about 3 minutes.
Step 2Add the dried beans, water and bay leaf. Bring to a simmer, stirring occasionally. Cover tightly and bake in the oven for 1 hour. Add the salt, stir and continue cooking, covered, until the beans are tender, 45 minutes to 1 hour. The beans should be like a thin stew; if necessary, add more water, one-quarter cup at a time. Remove the bay leaf and discard. Season to taste with more salt if necessary, and freshly ground black pepper. (The dish can be prepared up to this point a day ahead and refrigerated, tightly covered.)
Step 1Reheat the beans, if necessary.
Step 2Heat the olive oil over medium heat in a large skillet that has a tight-fitting lid. Add the garlic and parsley and cook until fragrant, about 3 minutes. Add the white wine and reduce to a thin syrup, about 3 minutes. Add the crushed tomatoes and cook until slightly reduced, about 5 minutes.
Step 3Add the shrimp and clams, cover tightly and raise the heat to high. Cook, frequently giving the pan a vigorous shake (holding the lid on firmly), until the clams have opened, about 5 minutes.
Step 4Gently stir the clams and shrimp into the warmed beans and heat through. Season to taste with more salt, if necessary. This makes about 12 cups stew. Ladle the stew into shallow soup or pasta bowls and sprinkle each with about 2 teaspoons of the chopped pickled peppers and the parsley if using. Serve immediately.