Preheat oven to 450
On a large sheet pan, add 1/2 cup of the chopped leeks, 1/2 of the chopped fennel, carrots, and broccoli. Season with olive oil, salt and pepper. Mix with hands and bake for about 20 minutes until cooked and slightly crispy. Remove and set aside.
In a large stockpot, add a little olive oil and cook the leeks and fennel for about 6 minutes. season with a little salt and pepper.
Next, add the potatoes, chopped rosemary, and broth. Put the lid and cook for about 15 minutes or until soft.
Add the milk and creamer and some more salt and pepper.
Using an immersive blender, blend the soup until smooth, Add the fronds of the fennel and dill and season with salt and pepper if needed.
Serve the soup and top with the roasted veggies.