Saute shallot garlic in a stockpot with olive oil for 2 minutes. Add salt and tomato paste; cook 1 minute. Add beer and cook until absorbed. Add chicken broth; bring to a boil. Add tomato and halibut fillets cut into chunks; simmer, covered, for 5 minutes. Add mussels and peeled fresh or thawed frozen shrimp and cook 5 minutes more. Add parsley before serving.