½ cup shredded Swiss cheese
2 tbsp. extra-virgin olive oil
¼ tsp. ground pepper
1 bunch scallions, sliced, white and green parts separated
½ cup chopped turkey kielbasa (3 ounces)
1 cup fresh rye breadcrumbs, preferably seeded rye
1 cup refrigerated sauerkraut, squeezed dry and chopped
2 large eggs, beaten
1 2½- to 3-pound spaghetti squash, halved lengthwise and seeded