Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Once shimmering, add diced onion and cook for 3-4 minutes until softened and translucent, stirring occasionally. This aromatics foundation prevents the finished dish from tasting flat or one-dimensional.

Add minced garlic and cook for exactly 90 seconds, stirring constantly to prevent browning. The garlic should release its fragrance but remain pale—this ensures it dissolves into the broth rather than creating burnt, bitter notes. This is CIA-level attention to timing.

Pour white wine into the pot and bring to a simmer for 2 minutes to burn off alcohol while concentrating flavors. Scrape the bottom of the pot with a wooden spoon to release any browned bits stuck to the surface.

Add seafood broth, diced tomatoes with their juice, sliced fennel, diced zucchini, and red bell pepper. Stir in saffron threads, bay leaves, and dried thyme. Bring to a gentle boil, then reduce heat to maintain a soft rolling simmer. This beautiful summer seafood stew recipe develops better flavor when cooked gently rather than aggressively—aggressive heat breaks down delicate proteins prematurely.

Let vegetables cook for 8-10 minutes until fennel becomes tender but still maintains slight firmness. Taste and adjust seasoning with salt and pepper, keeping in mind that the broth will intensify slightly as seafood releases its minerals.

Add fish chunks first, scattering them across the surface rather than dumping them in one spot. Let them cook for 4 minutes without stirring—this initial cooking firms the exterior. Then add shrimp and scallops, gently folding everything together. Cook for exactly 3-4 minutes until shrimp turns opaque and scallops become tender and white throughout.

Remove from heat immediately once seafood reaches proper doneness—overcooking by even 60 seconds toughens proteins irreversibly. Taste once more and adjust seasoning. Remove bay leaves before serving.