Preheat oven to 425°F. Grease a 9in round deep dish pie plate or a deep sided 8x8in square casserole dish. Press cold, leftover stuffing/dressing into the bottom and slightly up the sides to form a bottom "crust". Bake in oven for 5 min. Remove and set aside (leave oven on).

Heat a medium saucepan over medium heat. Add butter when hot. When melted whisk in flour. Cook about 2 minutes to make a nice golden roux. Add milk, whisking to combine and keep from clumping. Stir in leftover gravy and veggies. Bring to a simmer for about 2 minutes to heat through. Turn off heat, add leftover turkey and stir gently to combine.

Reheat mashed potatoes in a microwave safe bowl for 1-2 minutes in microwave, or until just heated through so they will be easier to work with.

Gently pour filling into stuffing crust. Starting at the edges, dollop mashed potatoes in several little mounds all over the top. I actually have a tablespoon sized ice cream scoop that works perfectly for this, and makes the cutest little mounds of potato. You could even use a star tip on a piping bag. Get fancy with it!

Bake for 20-25 minutes or until potatoes begin to brown. Remove from oven. Let rest 5 - 10 minutes and enjoy a simple and easy day after Thanksgiving meal!

Optional: remove from oven at 20 minutes, top with 1 cup shredded cheddar cheese and return to oven for 5 minutes or until cheese is melted and beginning to turn golden brown.