Brown the sausage. Set a large pot or Dutch oven over medium heat. Add the sausage, breaking it into small pieces.
Cook until browned and no longer pink, about 6–8 minutes. If there’s excess fat, spoon off all but 1 tablespoon.
Sauté the aromatics. Add the onion and cook until translucent, 3–4 minutes. Stir in the garlic, fennel seeds, smoked paprika, and red pepper flakes.
Cook 30–60 seconds until fragrant.
Deglaze and add broth. Pour in a splash of chicken broth and scrape up any browned bits from the bottom. Add the remaining broth and bring to a gentle boil.
Add veggies. Stir in the zucchini (if using) and the chopped kale. Reduce to a simmer and cook 8–10 minutes, until the kale is tender but still bright.
Finish with cream. Lower the heat and stir in the heavy cream or coconut milk.
Warm through without boiling. Season with salt and pepper.
Brighten and serve. Stir in lemon juice if you like a fresh finish. Ladle into bowls and top with parsley or a sprinkle of Parmesan.