In lg skillet over medium heat, heat 1 tbsp oil. Add cabbage and cook until tender, about 10 min. In a 4-quart dutch oven, add 1 tbsp oil. Add bratwurst and apples and cook over med-high, stirring, for about 10 min. In bowl, whisk together 1/4 cup water and dijon mustard. Add to dutch oven. Bring to a boil, reduce heat and simmer until apples are tender. Stir often. In small bowl, combine sour cream and sage. Using a slotted spoon, transfer cabbage, bratwurst and apples to serving bowls. Whisk sour cream mix into cooking juices. Spoon sour cream mix over bratwurst mix and serve.