In a large skillet combine turnips, zucchini, cauliflower, onion, margarine, basil, garlic, 2 tablespoons water, 1/4 teaspoon salt, and 1/4 teaspoon pepper. Bring to boiling; reduce heat. Cover; simmer 8 to 10 minutes or till tender.
Uncover; cook 2 to 3 minutes more or till liquid is evaporated. Stir in tomato; heat through. Remove from heat. Top with cheese. Cover; let stand 1 to 2 minutes or till cheese melts.