Put the clams in a large saucepan with the wine, cover and cook for 5 minutes or until the clams have opened. Discard any that do not open. Remove the clam meat from most of the shells, keeping some in their shells for decoration, and reserve the juice.
Meanwhile, heat the oil in a large saucepan, add the lardons and cook for 2 minutes until browned. Stir in the onion, celery and carrot and cook for 5 minutes more until softened. Then add the potatoes, tomatoes, thyme, stock and the cooking liquid from the clams.
Cook for 12–15 minutes until the potatoes are soft. Season and return the clam meat and whole clams to the pan. Heat through and serve with crusty bread or crackers.