Once your potatoes are baked and cool enough to handle, preheat a soup pot and sauté the onion in the oil over medium-high heat until good and brown, about 10 to 12 minutes.
While the onion cooks, prep the potatoes: Slice the baked potatoes in half length-wise. Reserve three of the halves to make the potato wedges. Slice the rest into 3/4-inch chunks.
Once the onion is browned, add the garlic, fennel, thyme, sage, pepper, and salt. Cook for 2 more minutes, then add the wine to deglaze the pan. Add the chunks of potatoes and the broth, cover, and lower the heat a bit to bring to a low boil. Mix in the kale. Cover and cook for 15 to 20 more minutes.
Meanwhile, prepare the potato wedges:
Slice the reserved potato halves in half lengthwise so you have six pieces. Preheat a heavy-bottomed skillet over medium-high heat. Combine all the ingredients for the wedges, except for the oil, on a plate. Wet the potato wedges with a little bit of water and dredge the two cut sides in the cornmeal mixture.
Lightly coat the skillet with oil. Cook the potatoes on each cut side for about 4 minutes, or until golden and crispy. Spray with oil as you alternate cooking sides.The soup should be done by this point. Use a potato masher to mush up about half of the soup (for once, don’t use an immersion blender; it will make the potatoes pasty and yucky), add the milk, and mix. If it’s too thick, add a little water or vegetable broth. Ladle into bowls and top with a potato wedge crouton.
