Wash cauliflower, and break into flowerets. Cook, covered, in a small amount of boiling salted water about 8 to 10 minutes or until crisp-tender; drain. Saute onion, celery, and parsley in butter until tender. Remove from heat; add cornstarch, stirring until blended.

Dissolve bouillon cube in 1 cup hot water; gradually add to vegetable mixture, stirring constantly. Add soy sauce and pepper; cook over medium heat, stirring constantly, until smooth and thickened. Pour over cauliflower in serving dish.