Preheat the oven to 220C, fan-forced. Quarter the carrot lengthwise and cut into small chunks. Finely chop the celery. Cut the fish into bite-sized pieces and season with salt and pepper. Combine the tomato paste, Cajun seasoning and 1 tsp honey in a heatproof jug. Add 500ml (2 cups) boiling water and stir to dissolve.
Step 2 — Start soup
Heat 1 tbs olive oil in a medium saucepan over medium-high heat. Cook the carrot and celery, stirring occasionally, for 7-8 mins until softened.
Step 3 — Simmer soup
Add the Cajun stock mixture to the carrot mixture and bring to a simmer. Reduce the heat to medium. Add the fish and cook, stirring occasionally, for 5 mins or until cooked through. Remove the pan from the heat. Taste, then season with salt and pepper.
Step 4 — Bake bread
Meanwhile, cut the wholemeal rolls in half. Put on an oven tray, cut-side up, and bake for 5 mins or until lightly toasted.
Step 5 — Serve up
Spread the bread with the butter. Divide the fish broth among bowls and serve with the toasted bread. Enjoy!
Step 6 — Make it herby
If you have some on hand, scatter over a handful of coriander or parsley leaves for a burst of freshness.