I originally tried this recipe, approximated some measurements, and here's what happened.
The two smaller leeks on the left in the picture are the ones we're going to use. Rinse them, trim off those stringy roots, and chop them into small slices, from the white ends up to the green tips.
You already have an entire chopped sweet onion simmering in oil on the stove. Let it simmer until you have finished chopping two medium-sized leeks.
Next, you're going to add the chopped leeks to the onions on the stove, stir the leeks and onions together and let them simmer. Crush at least three cloves of garlic and add to the mixture in the large pot. Sautee this mess for about 7 minutes or until you're done cutting up and rinsing the potatoes.
Our vegetable stock turned out very dark and gravy-colored and oily this time. Which is perfect for soup stock. It had huge amounts of broccoli stem. We had this questionable broccoli whose ends had gone yellow and sort of slimy. I cut off the ends and threw the heart of the broccoli tree into the stew pot. There were also four giant orange carrots that had been kicking around in the fridge for a while. We had a fair amount of kale, the greens and some stems from a cauliflower, lots of green bean ends, some onion skins, the tough outer layer of onions and the heart of an onion, and the last of the last round of leeks. I was concerned that the heady result would overwhelm my fresh leeks and potatoes, so I nearly matched the amount of stock I put in with water.
Bring your soup to a boil, reduce heat to low, cover, and simmer for about 25 minutes or until potatoes are tender.
Here comes the fun part. Blend the soup in a blender. I only have a smoothie-maker, so I did it in batches. I added a teensy bit of rosemary before blending.