I love this and I’ve made it so many times now I don’t need a recipe.  Make it as cauliflower “steaks” or florets (a bit faster).
If you prefer an Indian vibe use a spice blend of 1 level tsp each of ground cumin, coriander and turmeric alongside the pepper and salt.

1 whole cauliflower, green leaves removed
1 heaped tsp ground sumac or sweet paprika
Freshly ground black pepper
Pink (Himalayan) salt
Extra virgin olive oil (about 2-3 tbs)

Roast cauliflower “steaks”
Preheat oven to 215c/200C fan
With the cauliflower standing on its stalk, slice it downwards into 1.5-2cm slices.  You’ll get 4-5 good “steaks” and some shards.
Brush the roasting tin with extra virgin olive oil lay the cauliflower slices on top rubbing them around a bit to coat with the oil without breaking them up.
Brush the tops with olive oil, sprinkle with the sumac/paprika, lots of freshly ground black pepper and a generous pinch of salt.
Roast 15-20 mins at 200C. It’s done when the edges are starting to char.

Roast cauliflower florets
Take out central thick stalk from the cauliflower and break into small florets.
Put in the roasting dish, drizzle on extra virgin olive oil, sprinkle on your spices, pepper and salt and toss to coat.
Roast 10-15 mins at 220c/fan 200c.
Its done when the edges are starting to char.

If you feel like a fancier recipe with a delicious middle eastern dressing go to my blog post https://www.annacollins.ie/oven-roasted-cauliflower-green-bean-salad/