In a large pot, heat the olive oil over medium heat. Add the sliced chorizo or Portuguese sausage and cook until browned, about 5 minutes.
Remove the sausage from the pot and set aside. Leave the rendered fat in the pot.
In the same pot, add the chopped onion and cook until translucent, about 5 minutes.
Add the minced garlic and cook for another 1-2 minutes until fragrant.
Pour in the chicken or vegetable broth and bring to a boil.
Add the diced potatoes and bay leaf. Reduce the heat to low and simmer until the potatoes are tender, about 15 minutes.
Remove the bay leaf from the pot. Using an immersion blender, blend the soup until smooth. Alternatively, you can blend the soup in batches using a regular blender.
Stir in the thinly sliced kale or collard greens. Cook for an additional 5 minutes, or until the greens are tender.
Return the cooked sausage to the pot and stir to combine. Season with salt and black pepper to taste.
If using, stir in the heavy cream for a richer texture.
Ladle the soup into bowls and serve hot.
Enjoy your meal!