Italian sausage and caramelized leeks bring great flavor to this classic hearty soup. Serve it with a tart shredded kale salad with apples and almonds for crunch.
Heat a Dutch oven or large pot over medium-high heat. Add oil and then leeks and carrots to heated oil. Saute until leeks are golden brown and carrots are tender, ~6 minutes. Add shallots and apple cider vinegar and saute until shallots are tender, 1 minute more. Add sausage and saute until sausage is cooked through, 4 to 5 minutes.
Add stock and mushrooms and bring to a boil. Reduce heat to medium and simmer soup until mushrooms are tender, ~8 minutes.
While soup simmers, slice apples into matchsticks. Whisk together olive oil, balsamic vinegar and maple syrup. Toss with kale, apples and almonds. Season with a bit of salt and pepper.
Taste soup and add additional seasoning, if needed. Ladle soup into bowls and serve with salad on the side.