Breakfast burritos from 16 egg casserole, how to cook everything uniformly?
Baked, covered, at low heat :


ovens self-regulate, so you're going to get a more consistent result each time than doing it on the stovetop.
covering will minimize evaporation, which will cool the top more.
low heat will minimize problems with the edges cooking before the middle ... but eggs also have this strange thing where it's more difficult to over cook them at low heat ... and it's not just an issue of carry-over cooking (which lower heat will help to minimize, too).


As for shape of the vessel, I'd go with a rectangular baking dish -- because then I could more easily portion out 16 equal sized servings than from a round or oblong vessel.