Cook rice if you haven't done so already. You can do this by taking 1/2 cup raw rice, wash and drain it. Place in a microwave safe bowl, add 1 1/2 cups of water and salt to taste if desired. Cover tightly. Cook on high for 20 minutes
In a large bowl beat eggs. Add rice, onions and UN-DRAINED tuna fish. Mix well. In small glass bowl - place butter. Microwave on high for 1 minute. Mix with the tuna along with thyme and crumbs. Mix well.
Spread mixture evenly in lightly greased 9" pie plate. Cover with wax paper. Microwave on high 9 - 11 minutes, rotating dish 1/2 turn after 5 minutes.
Serve in wedges, garnish with cheese and sliced tomatoes.