Bring a large pot of salted water to boil. Add tomatoes and boil for 20 seconds. Using a slotted spoon, remove tomatoes from pot, reserving the boiling water. Stir in saffron to the boiling water, remove from heat and cover to keep warm.

 

Peel, seed and roughly chop the tomatoes. Roughly chop together capers and anchovy. In a large Dutch oven or heavy pot with lid, heat oil, caper mixture, garlic and oregano over medium heat until oil is warm and fragrant, about 3 minutes. Stir in tomatoes and red pepper flakes, then add mussels and cook, covered, stirring occasionally, just until mussels open wide, stirring and checking frequently after 4 minutes. Using a slotted spoon, transfer opened mussels to a large bowl. (Discard any mussels that remain unopened after 10 minutes.) Remove pot from heat.

 

Detach and discard 1 half shell from 12 mussels (keeping meat attached to other half of shell). Set aside meat and 12 half shells. Remove remaining mussels from shells, discarding shells, and return shelled mussels and any juices to pot; cover to keep warm.

 

Return water to boil, add pasta and cook until just under al dente. Reserving 1 cup pasta cooking liquid, drain pasta. Add pasta and liquid to soup, bring to a simmer and cook, covered, until pasta is al dente, about 2 minutes. Serve warm, garnished with mussels on the half shell and basil.

 

NOTE:  Capunti can be puchased at specialty food markets or gourmetfoodexpress.com.