Preheat oven to 450°F. Toss potatoes, 2 Tbsp. oil, 1 tsp. salt, and ¼ tsp. pepper on an 18x13" rimmed baking sheet. Prick sausages all over with a sharp knife, then nestle among potatoes. Roast, turning sausage and tossing potatoes halfway through, until potatoes are lightly browned and just barely fork-tender and sausage is just cooked through, 12–14 minutes.

Meanwhile, whisk vinegar, mustard, honey, and remaining 6 Tbsp. olive oil, ¾ tsp. salt, and ¼ tsp. pepper in a large bowl. Pour about ¼ cup dressing into a small bowl or pitcher and reserve for serving. Toss greens in remaining (about 2 Tbsp.) dressing, using your hands to massage dressing evenly into leaves.

Scatter dressed leaves in an even layer over sausage and potatoes. Roast, tossing greens halfway through, until greens are tender and charred in places, 3–5 minutes.

Separate sausage, potatoes, and greens into sections to serve, if desired, or toss all together. Serve with reserved dressing alongside. Editor’s note: Head this way for more of our best sausage recipes →