Heat oil in pan, put onions & cook till soft. Then put garlic & cook until slightly golden.Add other ingredients of except butter. Cook for 2-3 min. Then add butter & saute for 2-3 min more. Keep aside when done.
Take one pre backed pizza base ( I always find in superstores) on microwave safe plate,make layers one by one -1#spread tomato sauce,2#cheese, 3#sausage mix, 4#tomato sauce,5#cheese. Finish with sprinkle of dry oregano.
Cover with a lid and microwave on 70% power for 2min 30sec. Serve hot. Enjoy.