How to Make It
Cook the sausage in a Dutch oven over medium-high, stirring often, until the meat crumbles and begins to brown, about 4 minutes. Add the onion and garlic and cook until the onion softens and the sausage is browned all over, about 4 more minutes.
Add the stock, stirring and scraping to loosen any browned bits from the bottom of the Dutch oven. Add the lentils, tomatoes, salt, and pepper and bring to a boil. Reduce heat to medium-low and simmer until the lentils have softened, 20 to 25 minutes.
Stir in the kale and cook, stirring constantly, until softened, about 1 minute. Serve with the baguette.