Place the washed quinoa in a medium saucepan with a cup of water and a pinch of salt. Bring to a boil, reduce heat to a low simmer, and cover. Cook for 15 minutes until quinoa is fully cooked. Remove from heat and set aside until needed.
Meanwhile, chop and prepare your greens and the other vegetables. For a quick way to prepare leafy greens, chop them up and place in a big bowl of cold water. Swish the greens around with your hands very well, then lift the greens out of the water to keep the dirt in the bottom of the bowl. If the greens are particularly dirty, repeat with fresh water. There is no need to spin the greens as you would with salad lettuce. When you are ready to cook the greens, lift them out of the water directly into the saucepan.
Make the quinoa soup
When you are ready to make the quinoa soup, heat the oil in a medium saucepan on medium heat. Add the scallion or onion, along with the garlic, and sauté until the garlic just starts to brown.
Add the water or broth and bring to a boil. Add the greens and red radishes, along with the prepared quinoa, fresh lemon juice, and a pinch of salt. Careful not to overcook the greens. You may not need to simmer at all, or you may need just a couple minutes until the greens are wilted and cooked to your liking. If you like, reserve a few radishes for a raw, crunchy garnish. (I like mine cooked.)
Turn off the heat and taste. Finish with freshly ground black pepper and salt to taste. Add more lemon if you desire. This soup is better when well salted.
Notes
Greens: This soup can handle almost any type of green you want to throw at it, and whatever is available. Choose from kale, beet greens, dandelion, sprouting broccoli, radish greens, endive, spinach, arugula, Asian greens, zucchini, watercress, or even asparagus.Fresh onions add a lot of flavor to this soup. To understand the difference between scallions, green onion, and spring onion, please see this article.