Preheat your oven to 450 degrees F. Chop the bottom off of the head of garlic so that the cloves are exposed. Place the garlic (exposed side-up) into a mold of a regular-sized muffin tin. Cover loosely with foil and place it in the oven. Roast the garlic for about 45 minutes or until fragrant and browned slightly. Remove from oven and let cool. Once cool enough to handle, release the cloves from the head by pressing firmly on the top. Set aside.

In a large pot or dutch oven, add the sausage. Heat over medium heat and cook until browned and cooked through. Remove the sausage with a slotted spoon and transfer to a plate, leaving the fat behind. Add the oil to the pan only if you find there is not enough fat left over from the sausage. Add the onion, carrots and celery. Cook until the veggies are tender, about 7-8 minutes. Pour in the chicken broth and add the cubed potatoes. Season generously with salt, black pepper and Italian seasoning. Bring the soup to a boil and then reduce to a heavy simmer. Cook until the potatoes are tender, about 20 minutes. Add roasted garlic cloves to the pot. Turn the heat off and discard the bay leaf. With your immersion blender (alternatively you may use a regular blender - see below), blend the soup until about half of the soup is pureed. You will still want some larger chunks of potato and veggies remaining. Turn the heat back on to medium and add the already-cooked sausage, half and half (or substitute) and the kale. Cook until the kale is wilted substantially, about 6 minutes. Adjust the seasoning to taste and remove from heat.

Serve the soup immediately garnished with fresh parsley. The soup is best served next day or throughout the week for a quick lunch!