Heat oil: Pour olive oil into a large pot and set over medium heat. Add garlic, onion, and crushed red pepper flakes. Sauté until fragrant, about 3-4 minutes.

Add wine: Pour in white wine, allowing it to reduce slightly while scraping up any flavorful bits. This should take about 2 minutes.

Mix in tomatoes: Stir in crushed tomatoes and fish stock (or clam juice). Season generously with salt and pepper.

Simmer flavors: Let the broth simmer over low heat for 15-20 minutes.

Layer seafood: Add clams and mussels, allow to cook a few minutes, then add fish and shrimp.

Check doneness: Cook until shellfish open and fish turns opaque, about 5-7 minutes. Sprinkle with parsley.

Serve hot: Ladle into bowls, garnishing with lemon wedges and serve with crusty bread.