Step 1

In a large skillet, heat the oil over medium-high heat.

Step 2

Add the sausage and cook, breaking it up with a wooden spoon and stirring frequently, for 2 to 3 minutes, until browned.

Step 3

Add the onion and garlic and cook, stirring, for 1 to 2 minutes, until the onion begins to soften.

Step 4

Transfer the ingredients to the slow cooker with the 6 cups broth. Cover and cook on low for 6 hours or on high for 3 hours.

Step 5

Remove and discard the rosemary sprig.

Step 6

Scoop out 1 cup of the broth, onion, and sweet potatoes, being careful to avoid the sausage, and transfer to a blender. Add the 1/4 cup cream, if using, to the blender, blend on high speed until smooth, and return the puree to the pot. Switch the slow cooker to high heat, add the kale, and simmer, covered, for 10 to 15 minutes, until thickened. Serve immediately.

Step 7

Transfer the ingredients to the pressure cooker add 5 cups of the broth and cook for 10 minutes. Let the pressure release naturally.

Step 8

Remove and discard the rosemary sprig.

Step 9

Scoop out 1 cup of the broth onion and sweet potatoes being careful to avoid the sausage and transfer to a blender. Add the cream to the blender blend on high speed until smooth and return the puree to the pot.

Step 10

Add the kale turn the machine to sauté on high bring the soup to a boil and boil for 1 to 2 minutes until thickened. Serve immediately.

Step 11

Let this simmer in a large pot on the stove 1 1/2 hours, covered over low heat.