Heat a large dutch oven or other soup pot over medium heat.
Add in 1 tablespoon of the Italian sausage and cook until browned. Using a wooden spoon, break up the sausage until fully cooked.
3. When fully cooked, remove sausage from the pot, place it on a plate with a paper towel and set it aside. The towel will help absorb the grease.
Dump out any excess grease and return the pot to the stove.
Add in the remaining 1 tablespoon of olive oil.
Add in diced onions and stir to coat in the olive oil. Continue to cook until they are soft and translucent. About 5 minutes.
Add in the carrots and celery and continue to cook for an additional 2-3 minutes. They should be soft with a bit of a crunch to them still.
Add in minced garlic, stir and cook for 30 seconds.
Add in diced potatoes, rosemary, salt, and pepper. Stir to incorporate everything.
Add in chicken stock, milk and add the sausage back in. Stir well and bring to a boil. Reduce to a light simmer and cook for about 15 minutes or until the potatoes are soft and tender.
While the soup is simmering, remove the stems from the kale and roughly chop them into pieces. It will seem like a lot of kale but don't worry it will wilt down as it warms up.
Once potatoes are soft add in the kale and cook for an additional 5 minutes.
If you prefer a thinner consistency add a little bit of water. Bring to temp and serve warm.