In Catalonia, a “zarzuela” can be one of two things: a type of Spanish musical theater production that involves storytelling, song, and dance or a hearty stew loaded with seafood in a spiced tomato broth. The latter took its name from the former, and it’s easy to understand why: Like a theatrical spectacular, a pot of zarzuela is vibrant, exciting to behold, and downright applause-worthy.
On the eastern coast of Spain, zarzuela is cobbled together from whatever seafood is freshest at the market that day—from monkfish to clams to prawns to scallops—and served as a festive centerpiece for gatherings or special occasions. An abundance of seafood feels undeniably celebratory, but it presents a challenge for the cook: When all the fish are cooked in the same pot yet each has a slightly different cooking time, it’s difficult to achieve uniform, perfect doneness throughout the stew. In my recipe, I’d need to be strategic about which seafood I chose to include and how I’d cook it.
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Science: Going for Gold
Zarzuela is one of many recipes in the Spanish canon that makes use of saffron, the delicate hand-harvested stigmas of the Crocus sativus flower. Saffron infuses food with a bitter, iodine-like flavor, but its more noticeable effect is that it lends a dramatic golden tinge to soups, stews, rice dishes, and sauces. This color is due to the carotenoid pigment crocin, a molecule that has sugars attached on each end. Carotenoid pigments are typically oil-soluble, but crocin’s sugar groups make it water-soluble instead, which is why saffron is able to release such vibrant color in water-based applications. Crocin is so potent that it can perceptibly color water even at a 1 to 1,000,000 ratio. –Alyssa Vaughn
Casting a Wide Net
Zarzuelas in Catalonia typically contain either mostly shellfish or mostly finfish, but I liked the thought of including both to make the mix in the pot as dynamic as possible. Sweet, briny shrimp and a flaky white fish such as cod were the obvious place to start; they’re easy to find at most grocery stores, and their textures play well together. To accompany them, I chose mussels (their ebony shells would contrast with the ruddy broth; their brininess would heighten the stew’s oceanic flavor) and squid (for its striking appearance and springy texture).
The stew’s main characters cast, it was time to fill out the supporting roles. I began by sautéing onion, red bell pepper, and garlic—zarzuela’s typical foundation—and then seasoned the mixture with the traditional accompanying spices: musky sweet paprika; earthy, smoky pimentón (smoked paprika); and delicate, grassy saffron. Catalan cooks then usually deglaze the pot with both white wine and a touch of an additional spirit such as sherry, rum, or brandy. I wondered if I could eliminate the liquor for simplicity, especially since only a couple tablespoons are called for, but when I made a version with brandy and one without and tasted them side by side, it was clear that the liquor added subtle, but necessary, complexity.
Technique: Arranging and Cooking the Seafood
Zarzuela’s symphony of seafood requires a bit of strategy, as mussels, cod, shrimp, and squid each cook at different rates. To ensure that none of the elements turn out over- or underdone, we start by adding just the mussels, as they take the longest to cook. Four minutes later, we add the cod, shrimp, and squid, quickly but gently stirring them into the broth. Finally, we put the cover on the pot and remove it from the heat—cooking seafood in residual heat provides insurance against overcooking. During a 15-minute rest, the temperatures of the seafood and the cooking liquid equalize, gently cooking the seafood to perfect doneness.
I heavily reduced the wine and brandy to concentrate flavor and drive off the harshness of the alcohol, which necessitated adding more liquid to achieve the proper volume and consistency in the broth. Two large tomatoes, grated to a pulp on a box grater, contributed some volume and plenty of color, but I still needed about 2 cups more liquid. Water was out—it diluted the stew’s seafood flavor too much—and I was hesitant to call for boxed seafood stock, as its flavor varies widely among brands. I decided to turn to a more reliable product: clam juice. Two bottles was just enough to deepen the flavors of the ocean in my stew.
The stew’s volume adjusted, it was time to thicken the broth. Catalan cooks typically use a picada—a granular mixture of nuts, olive oil–fried bread, garlic, and often spices—to add body to soups and sauces and amp up flavor. While I love the perky freshness of a traditional picada, I opted to strip back the approach in this recipe so as not to outshine the delicate seafood flavors of the broth. A mixture of almonds and parsley, ground together in my food processor, thickened the broth and added subtle, but not overwhelming, flavor.
Easy Does It
Time for my final challenge: developing a cooking method that would bring fish, shrimp, mussels, and squid all to the perfect stage of doneness. First, I tried adding them to the simmering broth in stages, adding the longest-cooking component (the mussels) first and then adding the chunks of cod, the shrimp, and the squid in turn. This method seemed logical on paper, but the cod and squid were woefully overcooked in practice. I shuffled the order in which I added them to the pot and adjusted cooking times, but I always overcooked the cod.
Then, I remembered my colleague Annie Petito’s recipe for moqueca, a Brazilian shrimp and fish stew, in which she cooks the seafood in the hot broth entirely off the heat, a gentle method that prevents the seafood from overcooking. For my next test, I gave the mussels a head start by cooking them for a few minutes alone and then added all the rest of the seafood, gently stirring it into the broth, putting the cover on the pot, and removing it from the heat. After a gentle 15-minute cook, I had it: plump, briny mussels; moist, flaky cod; springy shrimp; and tender and lightly snappy squid, each playing their part perfectly in my harmonious zarzuela.