Place the olive oil in a heavy-bottomed soup pot over medium heat. Add the garlic and saute until lightly browned. Add the anchovy, capers, and oregano and saute for 1 minute. Add the tomatoes, chicken stock, mussels, saffron, and red pepper flakes. Cover the pot and cook for 8 minutes.
While the mussels are cooking, cook the pasta in a large pot of salted water. When the mussels are cooked, remove them from the pot with a slotted spoon. Discard any unopened ones and remove the rest from their shells. Discard shells and any unopened mussels. Strain the cooking liquid through a double thickness of cheesecloth to remove any sand and impurities. Return liquid to the clean pot.
Drain the pasta, placing the shelled mussels back into the soup with the pasta, adjust the seasoning, allow to simmer for 3 to 4 minutes and serve. Don't forget to provide plenty of crusty bread to mop up
Recipe courtesy of David Ruggerio, from his Little Italy Cookbook