Bring wine, garlic, leeks and crushed
red pepper to boil in heavy extra-large
pot. Add clams. Cover and cook until
clams open, about 9 minutes. Using slotted
spoon or tongs, transfer clams to 4 large
bowls (discard any clams that do not open).
Stir tomatoes and pesto into pot and bring
to simmer. Stir in herbs de province (optional).
Ladle pesto broth over clams and serve.