Drain oysters, reserving liquor; set aside.
Sauté mushrooms, celery, and green pepper in butter in a large saucepan until tender. Stir in reserved oyster liquor, tomatoes, and next 8 ingredients; bring to a boil. Reduce heat; cover and simmer 30 minutes.
Combine cornstarch and water; mix well. Gradually add to tomato mixture; stir well. Bring to a boil. Reduce heat; stir in oysters. Simmer, uncovered, until oyster edges curl.
Spoon over hot cooked rice in individual serving bowls.
Oxmoor House Homestyle Recipes