Skillet Gardner's Pie - A Great Way to Use Up All of those Veggies

The other day I realized that I had a ton of veggies that needed to be eaten, and only small amounts of each thing.  I've been wanting to make a Shepherd's Pie for ages, so I decided that this would be a great time to do it.  I used this recipe as a guideline, but changed it a lot to use what I had on hand.  Mine had green beans, turnips, collards, carrots, onions, and mushrooms.  I also used leftover mashed potatoes.

It turned out really well, I'm sure I'll make it again!   

What is one of your favorite recipes for using up a bunch of leftovers?