A Spanish zarzuela is a big, hearty broth similar to a French bouillabaisse, seasoned with saffron and studded with lots of seafood. Break the bank and purchase real saffron threads rather than the ground powder, which is often adulterated with other less costly spices, like turmeric.
Heat the olive oil in a large pot over medium heat. Saute the onions until translucent, about 5 minutes. Add the bell peppers and garlic and cook 2 to 3 minutes, or until softened. Stir in the prosciutto and cook 3 minutes longer, stirring occasionally. Add the tomatoes and increase the heat to medium high. Cook, stirring frequently to prevent scorching, until all the liquid has evaporated. Stir in the ground almonds, thyme, saffron, rosemary, salt, black pepper, red pepper flakes, and wine. Bring to a boil and boil until most of the wine has evaporated.
Pour in the fish stock and lemon juice. Bring to a boil and stir in the clams and mussels. Reduce the heat to medium, cover, and cook 10 minutes. Add the shrimp, scallops, and squid and cook 5 minutes longer. Remove and discard any unopened shellfish. Adjust the seasonings and bring to the table. Serve family style in soup bowls, with the lemon wedges and toasted bread.