1 medium (8 ounce) yellow or russet potato, scrubbed clean and chopped 1 garlic clove, minced 1/2 teaspoon kosher salt 2 cups vegetable stock, chicken stock, or water 1/2 bunch kale (6 to 8 big leaves), preferably dino, lacinato, or Tuscan 1 teaspoon lemon juice or cider vinegar 1 to 2 large eggs Salt and pepper (Thyme, oregano, Italian parsley optional) Grated Parmesan cheese, extra-virgin olive oil, or yogurt, to serve
Combine the chopped potato, garlic, salt, and stock (or water) in a medium saucepan over medium-high heat. Bring to a boil, then reduce the heat to simmer.
NOTE: For a heartier soup you can first sauté onions, celery, carrots before adding broth and potatoes. A handful of pasta could also be added.
While the potatoes start to cook, chop the kale. Remove any thick, tough stems and chop them into small pieces. Add the chopped stems to the pot with the potatoes and simmer for 2 minutes.
Stack the leaves of kale on top of each other. Slice them crosswise into thin ribbons, and add them to the pot with the potatoes and kale stems. If necessary, add more stock or water to the pot to just about cover the kale.
Cover the pot and let the soup cook for 8 to 10 minutes. The soup is ready when the potatoes are easily pierced with a fork, and when a ribbon of kale has become tender, but has not yet become stringy or pulpy. Stir in the lemon juice or vinegar. Taste and season with more salt and fresh cracked pepper. Also add more stock or water if a more brothy soup is desired.
To finish, crack the eggs gently into the soup. Ladle some of the soup broth on top of the eggs to submerge them. Put the lid back on the pot and cook for 4 minutes. When done, the whites of the eggs should be opaque, but the yolk should still be soft. If the eggs break into the soup before they are poached, just use a fork to swirl them into the soup, like egg drop soup.
Carefully spoon the eggs into a soup bowl. Ladle the soup on top. Finish with a sprinkle of Parmesan cheese, a drizzle of olive oil, or a spoonful of yogurt.