Here's a recipe I tried one night for a Polish Dinner I made for our family. Serve with Potato and Cheese Pierogi or Mashed Potatoes.
2 tablespoons butter
2 tablespoons olive oil
1 cup sweet yellow onions, chopped
2 pounds kielbasa, 3-inch slices
32 oz. sauerkraut, drained
14 oz. crushed tomatoes
1/2 teaspoon salt
1/2 teaspoon ground black pepper
In a large skillet over medium heat, melt butter and olive oil. Add onions and kielbasa and cook until onions are translucent and kielbasa has browned, about 8-10 minutes. Add sauerkraut, crushed tomatoes, and salt and pepper. Bring to a boil, and then simmer for 12-15 minutes. Serves 4-6.