Heat the butter/olive oil in the saucepan on a medium-high heat. Do not overheat it. Add leek and sauté for 2-3 minutes and add thyme and rosemary twigs. Sauté for another 3-4 minutes until the leek becomes soft.
Add potatoes and cauliflower into the pot. Mix.
Add enough water to cover your vegetables. Bring to the boil and reduce the heat to low so the water just bubbles. Cook for 10 minutes or until the potatoes and cauliflower are very soft. Make sure not to boil it.
Carefully transfer the soup into the blender, and blend on high until the soup is nice and creamy. It will take 20 seconds in a Thermomix on speed 8.
Transfer back to the saucepan. Your soup is ready to serve. Enjoy!
Video
Notes
If you don't have leek on hand, one regular onion will work too. Just make sure you sauté the onions until they are REALLY soft to get all the sweetness.
I made cauliflower-parmesan "chips" to serve with the soup. To make them, I cut cauliflower into thin slices and fried them in a frying pan in a small amount of olive oil until the cauliflower had a nice brown colour on both sides. I sprinkled grated parmesan and fried for another minute. Done!
This soup also goes well with gluten-free croutons or crispy chickpeas.
What would you top it with? Let me know in the comments below ⇓⇓⇓