We have Italian immigrants living in San Francisco to thank for cioppino, a tasty tomato-based seafood stew.
In a large pot, heat 3 tbsp. oil over medium. Add the sliced fennel, the onion, and garlic; season with salt and pepper. Cook, stirring occasionally, until the vegetables are tender, about 10 minutes.
Stir in the wine. Cook over medium-high heat until almost evaporated, about 5 minutes. Add the tomatoes and their juices, clam juice, and crushed red pepper. Cook, crushing the tomatoes with a spoon, until the mixture thickens, about 10 minutes; season generously.
Reduce heat to medium-low. Add the mussels and fish. Simmer, gently stirring occasionally, until the fish is flaky and the mussels open, about 6 minutes. (Discard any mussels that don’t open.)
Divide the cioppino among shallow bowls. Drizzle with the remaining 4 tbsp. oil. Top with the parsley and fennel fronds.