Heat olive oil in a large saucepan over medium heat.

Add shallots, saffron, fennel seeds, and garlic to the pan.

Cook for 4 minutes or until the shallots are tender.

Add clam juice, Pernod, and tomato paste to the pan.

Bring the mixture to a boil.

Reduce heat and simmer for 15 minutes.

Stir in tarragon, salt, pepper, potatoes, and fennel bulb.

Cover the pan and cook for 10 minutes.

Add clams to the pan.

Cover and cook for 10 minutes, or until the clams begin to open.

Stir in shrimp.

Cover and cook for 2 minutes, or until clams are fully open and shrimp are cooked through.

Discard any unopened clams before serving.