4 medium red potatoes (about 1-1/2 lbs)
1 1/2 cups thinly sliced onion
1 cup chopped celery
1/2 cup dry white wine
1/4 cup chopped fresh parsley
1 1/2 Tbsps tomato paste
1 Tbsp olive oil
1/2 tsp dried thyme
1/4 tsp salt
1/4 tsp saffron threads
1/4 tsp pepper
1/8 tsp fennel seeds
2 (8-ounce) bottles clam juice
2 garlic cloves, minced
2 lemon slices
1 (14.5-ounce) can no-salt-added whole tomatoes, drained
1 bay leaf
1/2 lb medium peeled shrimp
3/4 lb cod or other lean white fish fillets, cut into 1-inch pieces