How to Make It
Combine seafood stock, water, wine, and saffron in a medium saucepan. Bring to a simmer over high; cover and reduce heat to low. Keep over low heat until ready to use.
Pulse onion, bell pepper, tomatoes, and garlic in a food processor until finely chopped, 6 to 8 times.
Heat 1 tablespoon of the olive oil in a 15-inch paella pan over 2 burners on medium-high. Add shrimp to the pan; sprinkle with 1/2 teaspoon of the salt. Cook until the shrimp are golden on both sides, 1 to 1 1/2 minutes per side. Remove from pan, and set aside.
Add the onion mixture, squid, and remaining 1 teaspoon salt to the pan; cook, stirring occasionally, until nearly all the liquid evaporates, 7 to 8 minutes. Stir in paprika, and cook 2 more minutes.
Add rice and remaining 1 tablespoon olive oil. Cook, stirring constantly, until rice is slightly translucent, about 1 minute. Remove 1/2 cup of stock mixture, and reserve for use in Step 6; stir remaining stock mixture into paella.
Add squid ink, and stir just until rice is evenly distributed. (Do not overstir.) Cook over medium-high, 15 minutes, without stirring. Rotate the pan to ensure even heating. If paella begins to look dry in parts, add reserved stock mixture to that area, 1 to 2 tablespoons at a time.
Add clams, hinge side down, equally spaced around the pan. Cover and cook 4 minutes. Add mussels, hinge side down. Cover and cook another 4 minutes. Distribute shrimp evenly in pan, and cook another 4 minutes, uncovered. Increase heat to high, and cook, without stirring, 2 minutes. Remove from heat; cover with aluminum foil, and let rest 10 minutes. Top with parsley. Serve with lemon wedges.