3. Add drained kohlrabi and red pepper to onions. Cook, stirring, to brown the kohlrabi, about 5 minutes. Stir in greens, ¼ cup water, cumin and ¼ teaspoon salt; cook and stir, 2 minutes. Stir in sausage and garlic. Cook, covered, to heat everything through, 2 to 4 minutes. Add pasta if using and heat through, about 2 minutes. Serve with splashes of vinegar, if desired.