1 Set the oven to 185 degrees.
2 Trim the cauliflower, keeping some of the stalks to roast as well, then cut into 2cm steaks. Put the cauliflower flat on a large roasting tray with some of the leaves interspersed. Drizzle with two-thirds of the oil, season and turn to coat. Roast in the oven for 20 minutes.
3 Meanwhile, whisk together the buttermilk, harissa, orange juice and zest, and smoked paprika.
4 Remove the tray from the oven, then lay the fish on top of the cauliflower.
5 Spoon the dressing over the fish along with the remaining olive oil and season. Scatter over the almonds, then put back in the oven for 15 minutes. It might be a little longer, depending on the thickness of the fish – don't be afraid to peek into the flesh if you're unsure.
6 Spoon on to warm plates with a scattering of torn mint on top.