Sauteeing removes the flavor from the veggies and the flavor ends up being left in the pan, especially the onions. If you want to taste them, mince them up really fine and either put them in raw (they'll cook along with the meat) or steep them in a little water in the microwave for two minutes. Thank me later.
I'm going to go ahead and side with Panthro on this one. I prefer the flavor/texture of lightly sautéed vegetables to raw or blanched veggies. To each his own.
I think Panthro's 30-45 prep time estimate is more realistic than a 10 minute prep time. Getting everything out of the fridge, organized, unwrapped, pre-heating the oven, washing your hands like 10 times while handling raw meat, chopping onions, peppers, etc., mixing everything together, moving it to the pan, prepping the side dishes while washing your hands again so as not to cross contaminate, then you have clean up. That poo takes time.