Soak the clams in salt water for 1 hour to get them to release any sand. Wash thoroughly and put by.
Chop up the onion, garlic and pepper. Grate the tomatoes.
Gently fry the chopped onion over a low heat for 10 minutes and add the chopped garlic, pepper, bay leaf, saffron and grated tomato.
Once it is all lightly fried (about 5 minutes), add the warmed fish stock and clams. When the clams start to open, turn off the heat.
Top off with toasted bread croutons and chopped parsley.