I first made this soup once when I had a whole head of cauliflower to use up quickly, and no one to eat it but me. It was very good fresh, and kept fairly well. I do not know how well it would freeze though.
To achieve a superior texture, you really have to use a decent blender. Stick blenders and food processors just don’t crush the almonds completely, and you end up with a gritty texture.
As with most soups, exact proportions of ingredients are not crucial, and improvisation is certainly appropriate. The carrot especially make it somewhat off-white, so leave them out if you would prefer a pure white soup. Personally, I really like the added sweetness they give the soup.
Also, white pepper will maintain the white color, but if you don’t mind black specks in your soup, feel free to use black. I prefer the flavor of white pepper in this soup.
Finally, if you are concerned about your milk curdling, you may want to use just a small amount water for the initial simmering instead of milk, then add the milk when blending the soup. I have not had this happen with this dish, but have with some other long cooking dishes that contain milk.