Peel and trim 3-4 onions, then dice. You want 2 Cups.
Heat 3 T. olive oil (or butter) in a large, heavy-bottomed pot.
Add the onions and saute over medium heat, stirring, until they soften completely and start to brown. Add a dash of red chili flakes if you like.
Minced 3 cloves of garlic and dice potatoes to make 2 C. Add the potatoes and garlic to the pot. Stir for a minute or two, then add 6 C. vegetable broth. Bring to a boil and then lower to a simmer.
While the potatoes are cooking, remove the stems from 1 bunch of Kale leaves. Slice the leaves crosswise, then roughly chop into small pieces.
When the potatoes are completely soft, add the Kale to the pot and stir to combine. Simmer for 5 minutes.
Drain 1 can of Cannelini or other white beans and rinse in a colander. Add to the soup. Cook for another 5 minutes.
If you like the soup creamy, use a hand-blender to partially or fully puree it.
Season the soup generously with salt and black pepper. Serve with a lemon wedge for squeezing into the soup.