Melt the bacon grease in a soup pot over medium high heat, and brown the sausage. Using a slotted spoon, remove the sausage from the pot once it is browned, leaving the cooking fat behind in the soup pot. There needs to be a good tablespoon of fat in the pot leftover from cooking the sausage – if there isn’t, add a little more bacon grease, butter, or olive oil so you can cook the veggies.
Over medium heat, saute the onion, carrot, and celery in the leftover sausage cooking fat with a pinch of salt, until the veggies are soft and sweet, around 7 minutes or so.
Add the garlic and flour and cook for 1 minute.
Add the bone broth and potatoes, stir to combine, and put the lid on your pot. Bring the soup to a simmer, and cook until the potatoes are very soft - about 10 minutes. Stir the soup every few minutes to be sure the potatoes don’t stick to the bottom.
Once the potatoes are soft, stir in the cooked sausage and the chopped spinach to wilt in. If you are using kale, you’ll need to cook it down a few minutes to soften.
Turn the heat off, add the coconut milk, and then salt and pepper the soup to your taste.