IIUC, while the water heats faster, it has a lower upper limit (the boiling point), while oil and fat keep getting hotter. Source: I have ruined a few plastic

IIUC, while the water heats faster, it has a lower upper limit (the boiling point), while oil and fat keep getting hotter. Source: I have ruined a few plastic containers by heating greasy food in the microwave, because the fat easily gets hot enough to melt the plastic. Homemade Bolognese sauce seems particularly dangerous in this regard, because it is both acidic and greasy, and that will absolutely EAT plastic. P. S. Even if you don't damage the plastic per-se, heating oily food in the microwave in a plastic container isn't a good idea, quite a few nasty compounds will leach into the oil more readily than into water.