Spread the cauliflower out on a baking tray in one layer and drizzle with the olive oil. Roast for 15 to 20 minutes or until the cauliflower is golden and almost caramelised.
1 medium cauliflower, 2 tablespoons olive oil
At the same time, boil the potato chunks until they are soft (about 15 minutes). Also warm the milk in a small saucepan with one of the thyme sprigs or the dried thyme.
1 medium potato, ⅓ cup milk, 2 thyme sprigs
Put aside a small handful of the roasted cauliflower florets. Then put the rest into the bowl of a food processor and blend with a bit of the warm milk (thyme sprig removed!).
Add the potato, butter, cheese and as much of the rest of the milk as you need to blend to a smooth puree.
2 tablespoons butter, 4 tablespoons grated cheese
Finally, grind in plenty of salt and pepper and blend for a couple more seconds.
salt & black pepper
Scrape the mash into a nice serving dish. Top with the reserved cauliflower florets, a sprinkle of fresh thyme leaves (if using fresh) and a drizzle of olive oil.
Video
Notes
Roasting the cauliflower in your air fryer
Got an air fryer? Check out this recipe for air fryer cauliflower if you'd like to make roasting the cauliflower slightly quicker and easier.
Making your mash ahead
If you cover your finished dish of mash, it keeps warm in the oven really well until you’re ready to eat.You can even make it up to 3 days before and take it along to a party/event. Just warm it through in a microwave just before serving (try 3.5 minutes at 80% power).
Cheese
This is ‘cheesy’ enough for us, but go ahead and add more cheese if you want your mash to be super cheesy. Alternatively, swap the 4 tablespoons of ordinary grated cheese e.g. cheddar for something stronger like parmesan. I'd use just 2 tablespoons of parmesan, though. To make this cauliflower mash vegan, you can even skip the cheese and butter altogether and just add a big drizzle of olive oil instead. Yum!
How to serve this cauliflower mashed potatoes
I sometimes serve this with sausages, vegetables (fresh or frozen) and gravy. It's also great with grilled or roasted meats or fish, a casserole, or any other dish you'd usually serve mashed potatoes with.