Heat the oil in a stock pot until just shimmering and add the onion and leek.
Cook over med-low until translucent and fragrant but do not brown, 5 minutes.
Add in the tomatoes and garlic, cook 5 more minutes.
Add in the rest of the ingredients. Give a stir, and simmer gently 30 minutes. Strain well, pressing solids to release liquid with back of a ladle.
Season to taste with the juice of half a lemon and additional salt if desired. It should be delicious enough to eat on it’s own at this point. Set aside.
While the broth simmers, make the rouille.
Combine the two oils in a pourable measuring cup.
In a bowl set on a wet towel to keep it from sliding, whisk the egg yolk with the mashed garlic clove & salt and cayenne.
Add the tablespoon of Pernod Classic and whisk to combine.
Slowly, drop by drop, add the oils to the mixture until an emulsion forms.
Once an emulsion forms, you can slowly add the oil in a thin stream, periodically whisking in some of the lemon juice until it’s all combined. Alternately, it can be made in a blender following the machine’s instructions for a mayonnaise.
To assemble the soup, bring the broth back to a simmer in the stock pot.
Add the potatoes and fennel. Simmer 5 minutes.
Add the white fish and simmer another 5 minutes.
Add the mollusks, the clams and mussels, cover and cook until JUST open, about 3 minutes.
Add the scallop and shrimp, turn off the heat, and allow to cook through (3-6 minutes).
Top with fennel fronds and serve with toasted baguette slathered with the saffron rouille and serve immediately with additional rouille and bread on the table.
Instructions For Mayo In a Vitamix:
Combine the two oils in a pourable measuring cup.
Place egg yolk, mustard powder, salt mashed garlic, saffron, cayenne, lemon juice, and Pernod Classic into the Vitamix container in the order listed and secure lid.
Select Variable 1.
Turn machine on and slowly increase speed to Variable 10, then to High. Blend for 10 seconds.
Reduce speed to Variable 8.
While machine is running, remove the lid plug and pour in the oil in a thin, steady stream through the lid plug opening until completely used and mixture thickens (about 30 seconds). If mixture appears to be getting to thick, sprinkle a tiny bit of the warm water in.
Stop machine and stir in any oil sitting on top.