Slice the potatoes into ¼" thick rounds. You can halve or quarter the rounds if they're too big for your preference, but for medium potatoes I usually use the full rounds.
In a large pot or dutch oven over high heat add the bacon and cook until crisp. Remove to a paper-towel lined plate to drain. Drain excess fat but don't wipe it entirely clean. Leave a little bit of the oil in the pan.
Add the sausage to the pan and break up into crumbles. Cook until crisp and cooked through. Remove to a bowl for later use. Drain excess fat, but don't wipe entirely clean.
Add in the diced onion and sauté until translucent and fragrant.
Add 4 cups chicken broth and the sliced potatoes. Cook for 10 minutes or until potatoes are fork tender.
Turn the heat down and add back in the sausage crumbles. Add the greens and stir. Spinach will wilt immediately; kale may take a little longer.
Stir in ¼ cup cream, and season to taste. Add salt, and pepper, and optionally red pepper flakes for extra kick.
If the Kale isn't wilted yet, leave on low simmering heat for 10-20 more minutes or until wilted and soft. (If using spinach or you like the texture of Kale, remove from the heat.)
Remove from the heat and serve topped with parmesan cheese, and a side of crusty bread