Radishes - trimmed and cut in half, 1/2 red onion chopped, garlic, butter and dill. Roast together at 200C for 20 minutes or so, stir a couple of times.
Somewhere around 10 carbs (halve that by leaving out the onion) and less than 100kcal before adding the butter.
It's a really delicious replacement for roast potatoes. Will make it again soon.