UPDATE:  I made this again the other night with leftover roast chicken and gravy...it was fabulous!  The only thing I did different was to add re-hydrated dry wild mushrooms to the recipe and included the liquid the mushroom re-hydrated in along with some chicken stock, and the leftover gravy.  A must try!
I love Shepherd's Pie - just about any which way it is made.  And this recipe could not have been any easier, a great way to use up leftovers, so, so tasty.  The above picture, was actually from another Shepherd's Pie recipe because I forgot to take a picture of the current one.  Plus I even forgot to take a picture of the plated dinner!  Dang!  They both use the same garlic mashed potatoes, so all is forgiven, yes?
Previously, we had a Hormone Free/Antibiotic Free Oven Rump Roast for dinner.  There were six of us for dinner that night, and the roast was just over 3 pounds.  I thought it would be all gone, but in fact, we ended up having three meals from this roast.  So here is a price comparison.  When you consider the cost of $5.00 per lb. then having 3 meals to total 11 servings, that is a very reasonable price.  Plus, you just can not compare the flavor - the difference between this meat and Industrialized Beef from the regular grocery store is HUGE, as it is with all meat.  We have also found, after a few years of eating good quality meat, which I know I might now be sounding like a broken record... there is no going back.  We just can't do it, in fact, the taste of Industrialized meat is just plain awful.  I keep telling my family we have become "purists" - at least when it comes to food - which is fine by me. Our tummy's are very happy! 🙂
So this post does not really have a recipe, but more of a step by step process.
Leftover Roast Beef, cut into small pieces - about 1 to 1 1/2 cups worth
Leftover Garlic Mashed Potatoes (at least 2 1/2 cups worth)
Leftover gravy (I had about 1/2 a cup)
1 Tblsp. butter
Salt and pepper
6 crimini mushrooms, diced
1/2 a large onion, diced
2 carrots, diced
2/3 cup diced rutabaga
1 bay leaf
beef stock
2/3 cup frozen peas
In a saucepan, add the carrots, rutabaga, and enough beef stock to cover.  Season with salt, pepper, and add in the bay leaf.  Cover and bring to a simmer until the vegetables are tender.  Remove the lid and add in the leftover gravy stirring to combine.
Heat up a frying pan on medium heat, with a good knob of butter.  Add in the mushrooms and onions, sauteing until the mushrooms are golden and the onion is translucent.  Add the mushroom onion mixture to the pot of vegetables.  Keep on simmer to reduce the gravy to half.
Then add the roast beef, and frozen peas, and transfer to a casserole dish.
Top with Garlic Mashed Potatoes, and bake in the oven at at 350 degrees until bubbly and heated through.