Bring several inches of water to a boil in a large saucepan fitted with a steamer basket. Add potato to the basket and steam 5 to 7 minutes, until just tender when pierced with a fork or the tip of a paring knife. Set aside.
Meanwhile, brown sausage in a large nonstick skillet over medium heat, stirring with a wooden spoon and breaking up chunks, 3 to 4 minutes, or until pink is no longer visible. Scrape sausage onto a plate and set aside; cover with foil to keep warm.
Add oil in the skillet and return heat to medium-high. Stir in shallot and salt and cook, stirring often, for 30 to 90 seconds, or until fragrant. Add potatoes to shallots and cook, stirring occasionally, for 4 to 6 minutes, or until potatoes are mostly browned.
Add sausage and any accumulated juices, kale, syrup, and vinegar, and cook, stirring often, for 2 to 3 minutes, or until the kale is wilted and just tender and sausage is heated through. Season with pepper. Serve warm.