Tonight I'm making porkchops that consist of dredging/breading, a
quick pan fry to brown, then they finish in the oven in a cream of
mushroom soup sauce.

I'm also making a greenbean casserole that I haven't made before (this
month's Cook's Illustrated magazine).

This consists of blanching fresh green beans, then making a sauce with
fresh mushrooms, broth, cream, flour, etc., mixing it all in a dish
and topping with a mixture of bread crumbs and fried onions.

How much of this, if any, can I make ahead of time so I'm not doing
everything at once? Can I make the entire casserole and refrigerate
it?

Also, the chops bake at 350 and the casserole at 425, and I don't have
a double oven. What should I do?

Thanks!