Making this soup is pretty straightforward, and the base stores well for a couple days in the fridge. If you do want to eat this soup over the course of a couple days, however, toss in only as much pasta and shellfish as you plan to eat in one sitting. This prevents the seafood from overcooking and the pasta from soaking up too much broth.
1quartchicken stock,or freshly made shellfish or fish stock
1cupsseawater or salty tap water
5thinly sliced garlic cloves
1/2cupcoarsely chopped roasted red pepper
A healthy pinch of saffron,or 1 packet of saffron powder
1/2poundfregula pasta, or other small soup pasta
Grated zest of a lemon
If you are using wild mussels, scrub their shells and pull off their beards. You should not have to do this with farmed mussels. (Here's a video on the process from my friend Becky.) Scrub the shells of the clams, too.
Pour the seawater or salty tap water into a large, wide pot with a cover and bring it to a boil. Add the mussels and steam them open, removing each one just as it opens. This should take 3 to 5 minutes. Do the same with the clams. Pick out most of the meats from the shellfish; put them into a bowl with some olive oil. Leave a few mussels in the shell if you want — it makes the soup look more interesting.
Strain the shellfish broth though cheesecloth or a paper towel into a bowl and set aside. Crumble the saffron into it while it is still hot.
In a large soup pot, heat the olive oil over medium-high heat and saute the garlic for a minute or so. Add the cayenne, parsley, stock and shellfish broth and mix to combine. Bring it to a boil and add the fregula pasta. Simmer this until the pasta is nearly done, about 10 minutes.
Add the roasted red pepper, shellfish, sea beans (if using) and cook for another 3 minutes. Right before you serve, add the lemon zest and chives. Serve with crusty bread and a crisp white wine.