Usually I'll do something typical like take the leftover meat/vegetables and make it into a stew/casserole.

I think the most creative thing I did with leftovers was when I made some Cajun style pork chops.

I had some left over, so added bite sized chunks of spicy pork chop into my corn bread batter along with some cheese, honey, and jalapenos and baked it all into a big cornbread/casserole loaf.

It turned out pretty well, with the spicy meat and jalapenos playing off the cheese and honey.