This recipe is based on an interview with Matthew Raiford at his farm, Gilliard Farms, in Brunswick, Georgia. It is important to use untreated shrimp—those without added sodium or preservatives such as sodium tripolyphosphate—in this recipe; treated shrimp contain too much sodium and may have off-flavors. Most frozen E-Z peel shrimp have been treated (the ingredient list should tell you). If you don't have fine sea salt, you can use an equal measure of table salt. We developed this recipe using our winning 14-inch paella pan, the Matfer Bourgeat Black Carbon Steel Paella Pan; you can make this recipe in a slightly larger or smaller paella pan, but the texture of the finished rice may vary.

FOR THE SHRIMP STOCK: Combine water, shrimp shells, onion, garlic, turmeric, salt, paprika, peppercorns, and pepper flakes in large saucepan. Squeeze lemon into saucepan and add spent half to saucepan. Bring to boil over high heat. Reduce heat to medium-low and simmer for 10 minutes. Strain stock through fine-mesh strainer set over bowl, pressing on solids to extract as much liquid as possible; compost or discard solids. (You should have at least 6 cups shrimp stock; if not, add water to make up difference.)

FOR THE PAELLA: Press large sheet of aluminum foil over top of cold 14-inch paella pan to form lid shape; set foil aside. Sprinkle shrimp with ¾ teaspoon salt and pepper; set aside. Heat oil in paella pan over medium heat until shimmering. Add bell pepper, onion, and remaining ¼ teaspoon salt and cook, stirring occasionally, until bell pepper is beginning to soften and onion is lightly browned, about 10 minutes. Stir in garlic and cook until fragrant, about 30 seconds. Stir in rice and cook, stirring often, until rice is coated with oil and translucent at edges, about 2 minutes.

Stir in 6 cups shrimp stock and bring to boil over high heat. Cook, stirring occasionally, until stock has reduced to level of rice, about 8 minutes. Reduce heat to medium. Press clams hinge side down into rice mixture, arranging evenly in pan (do not stir rice from this point on). Cover with prepared foil lid and cook until clams just start to open, about 6 minutes.

Gently press shrimp into rice mixture around clams. Re-cover with foil and cook for 5 minutes. Remove paella from heat and let sit, covered, for 5 minutes. Sprinkle with parsley and garnish with lemon wedges. Drizzle with extra oil and serve.