Heat a large soup pot over medium high heat and cook the beef bacon until crisp then remove and reserve while leaving some rendered fat in the pot

Lower the heat and add the diced onion and minced garlic, stirring frequently until softened and fragrant

Season lightly with salt and pepper, then sprinkle in the flour and stir until fully absorbed and lightly cooked

Gradually pour in the vegetable stock while stirring constantly to create a smooth and slightly thickened base

Add the chopped rosemary and allow the soup to gently simmer until the flavors meld and the broth thickens

Place the barramundi fillet into the pot and cook gently until the fish turns opaque and flakes easily

Break the fish into chunks and stir in the corn, cauliflower, and heavy cream until well combined

Allow the chowder to warm through at a low simmer, then taste and adjust seasoning as needed

Serve hot topped with the crispy beef bacon and fresh parsley if desired