Normally I'd grill these but at 9° my grill won't get or stay warm enough and grilling in the garage kind of smokes up the whole house.

I have 5 sirloins that I think will go into the oven.  Maybe brown them first. 

How long, what temp?

Any suggestions.  My wife isn't going to want any complicated or messy suggestions.  I just eat the sirloins and don't want to put any cream, cheese, or other stuff on them.  I do season with some stuff that we like that has some salt and pepper among other things.