In a pot, heat the oil over medium heat and add the bacon. Stir until tender but do not brown.
Add onions, bell pepper and celery and sauté for 2 minutes.
Add tomatoes, fish stock, and Chinese sea bream and bring to a boil.
Add and stir in potatoes and reduce heat to medium-low and simmer until potatoes are tender, about 20 minutes.
Take out the fish head. Season with salt and pepper.
Add fish, shrimps, and clams and continue cooking until done.
Combine all together in a stock pot.
Bring to a boil then simmer for 30 min.
Strain into a plastic container & cool in ice bath.