Place cheese and peppercorns into Thermomix bowl and mill for 10 sec/speed 10. Set aside,
Place leeks and butter into Thermomix bowl and chop for 3 sec/speed 7. Sauté 5 min/Varoma/speed 1. Add potatoes, and chop few sec/speed 4.
Add water and stock powder and cook 15 min/100°C/speed 2-3 until potatoes are well cooked.
Add milk and cheese mixture and cook for a further 4 min/100°C/speed 2-3. Puree by bringing speed up slowly 30 sec/speed 8. The liquid is extremely hot and may spit as the speed increases, so use caution. Taste and add salt if needed. The cheese is pretty salty as is the stock powder, so you may not need any.
Serve immediately with bread or rolls of choice!
Serve immediately.