Stir-Fried Kohlrabi

1 kohlrabi, peeled
2 medium carrots
2 tablespoons peanut or safflower oil
1 cloves garlic, peeled and thinly sliced
1/2 inch piece gingerroot, peeled and thinly sliced
3 green onions, sliced
1 fresh chili pepper, sliced, optional
salt
2 tablespoons oyster sauce (optional)
1 1/2 teaspoons sesame oil & soy sauce, each

Slice kohlrabi and carrots into thin ovals. Heat oil in large heavy skillet; when it begins to smoke, toss in garlic and ginger. Stir once then add kohlrabi and carrots; toss and cook 2 minutes. Add green onions and chilies; stir-fry 1 minute, then pour in1/ 4 cup water. Cover, reduce heat and cook 3-5 minutes. Remove cover and toss in a little salt and the sesame and soy, and oyster if using. Serve with rice