Step 1

In a medium saucepan, bring the fish stock to a simmer. Transfer 1 cup of the hot cooking liquid to a measuring cup and crumble in the saffron. Add the fava beans to the remaining stock and cook over moderate heat until bright green, about 1 minute. Using a slotted spoon, transfer the favas to a plate. Squeeze the beans out of their tough outer skins. Cover the remaining stock; keep warm over low heat.

Step 2

In a large, deep skillet, heat the olive oil. Add the chopped onion and cook over moderate heat, stirring occasionally, until softened, about 7 minutes. Add the fregola and cook over moderately high heat, stirring frequently, until it is well coated with the oil, about 2 minutes. Add the clams, mussels and 1 cup of the hot stock and stir constantly until the shellfish start to open, about 4 minutes; discard any clams or mussels that don't open.

Step 3

Add the sherry and simmer until reduced by half, about 3 minutes. Stir in the fava beans, sliced red and green bell peppers, plum tomatoes, sun-dried tomatoes, thyme, bay leaves and rosemary. Add the remaining 2 cups of hot fish stock and the saffron-infused stock to the fregola. Lower the heat to moderate and cook, stirring frequently, until the fregola is just tender, about 10 minutes.

Step 4

Add the shrimp, squid and monkfish to the fregola and cook over moderate heat, stirring a few times, until the seafood is just cooked through, about 5 minutes. Discard the bay leaves and thyme and rosemary sprigs. Stir in the dill and season with salt and pepper. Serve the paella immediately in shallow bowls.