OPTIONAL (if you choose not to broil the sausage, skip to the next step): Arrange the sausage on a foil-lined sheet pan and broil, on low, for 3 minutes on each side, or until the sausage is slightly charred on the edges. Remove the sausage from the oven and set aside.
Cut the potato into quarters (lengthwise), then slice each quarter into slices 1/2" thick. Set aside.
Heat the olive oil and bacon slices in a 6-quart dutch oven over medium-high heat. Use a wooden spoon to break up the bacon pieces as they cook.
Add the onions and garlic to the bacon in the pot and cook the veggies until they appear glossy and translucent, about 3-4 minutes.
Stir in the potatoes, salt, sage, and pepper. Pour in the chicken stock, and use your wooden spoon to scrape any browned bits from the bottom of the pot.
Bring the liquid to a boil, then reduce the heat to medium-low. Cover the pot and allow the stew to simmer for 10 minutes.
After 10 minutes, add the sausage and kale to the pot. Cover and allow the stew to simmer for another 10 minutes, or until the potatoes are fork-tender and the kale has wilted.
Spoon the hot stew into individual bowls and top with a generous amount of the shredded cheese and slice of artisan bread.