Make the saffron aioli first. Crumble the saffron threads into the hot water in a small bowl. Let them steep 10 minutes.

Using either a stand or immersion (stick) blender, briefly buzz the garlic, lemon juice or vinegar, salt, and egg yolks to combine. Add the saffron and the water and buzz until smooth.

With the motor running, drizzle in the olive oil until the whole thing emulsifies into a mayonnaise-like consistency. Taste for salt and acid, adding a little lemon juice/vinegar and salt if needed. Note: If for some reason your aioli breaks, or is way too thin, put another egg yolk in a clean bowl, then, whisking constantly, drizzle the broken aioli into it. It should come back together and thicken to a mayo-like consistency.

Keep the aioli cold. It should last in the fridge for several days.

In a large pot over medium heat cook down the leeks, fennel, onion, garlic, and ginger in the butter until the onions begin to turn translucent.

Add the spices and allow them to bloom for a few minutes then deglaze with the Pernod and white wine. Reduce the alcohol down by half then add the remaining ingredients. Bring the stew to a simmer for around 30 minutes until the tomatoes start to break down and all the vegetables are tender. Taste the stew and adjust the seasoning with the salt and pepper if needed.

Add the shrimp, cod, scallops, clams, and mussels and simmer in the liquid until they are fully cooked, between 6 and 8 minutes.