I have Old Fashioned oat meal daily from the microwave. DW heats for 1 minute on high , one minute on level 6 , then 45 seconds on level 5. you do need a large bowl or it will boil over.
We use these soup size cups that hold about 20 oz of liquid so they can boil up without spilling over.
I take the cooked oatmeal and cover with a saucer for a good 5 minutes, add my warmed mile, walnuts and about 4 oz of blueberrys. EAT it is wonderful.