In a six- or eight-quart pot, sauté leek, zucchini, and potato in oil for 10 minutes, stirring occasionally.

Add the cauliflower, salt, and pepper and sauté another minute.

Add water just to cover vegetables and bring to a boil. Reduce to simmer and cook for 30 minutes.

Blend with an immersion blender until smooth. Top each bowl with caramelized pine nuts (see below), if desired.

Place sugar in a pot over a medium flame and let sit until it starts to turn golden, giving the pot an occasional shake to mix.

Spread the nuts on Gefen Parchment Paper.

Once sugar is dissolved, pour over the nuts and let harden. Break into small pieces and sprinkle on top of soup.