Lay out the deli beef slices on a clean surface and gently pat the sauerkraut dry using paper towels to remove excess moisture, which helps keep the roll-ups crispy.

Place a slice of Swiss cheese on each piece of beef, then add a small portion of sauerkraut on top, making sure not to overfill to prevent spilling during cooking.

Drizzle a small amount of keto Thousand Island dressing over the filling, then carefully roll each slice tightly into a compact roll-up, pressing lightly to secure the shape.

Heat butter or olive oil in a skillet over medium heat, allowing it to melt completely and coat the surface evenly for better crisping.

Place the roll-ups seam-side down in the pan and cook for a few minutes until the outside becomes golden and crispy, then gently turn them to cook all sides evenly.

Continue cooking until the cheese inside is fully melted and the exterior is crisp and slightly browned without burning.

Remove the roll-ups from the pan and let them rest for a couple of minutes so the cheese can settle slightly before serving.

Serve warm, optionally with extra dipping sauce on the side for added flavor.