1. In the bowl, with the UltraBlade blade, put the onion cut in half and blend for 15 seconds, speed 10.
2. Add the olive oil and heat for 3 minutes at 100°C (speed 2). Meanwhile, cut the leeks into slices.
3. When the timer goes off, add the leeks and blend for 15 seconds, speed 10.
4. Heat for 3 minutes at 100°C (speed 2).
5. When the timer goes off, add the carrots cut into slices, water, vegetable cube, salt, and pepper, and set for 20 minutes at 100°C (speed 2).
6. Add the cream and blend for 1 minute at speed 12.
7. Add water if necessary, adjust the seasoning, and blend for 30 seconds at speed 7.