Perogies, Perogies, Perogies, lol. I know most use riced potatoes in theirs but I use leftovers too.
Mix 2 eggs into a couple of cups of mashed potatoes, Add some onion or scallions, a pinch of garlic powder, salt and pepper to taste and enough flour to hold the mixture together. Using 2 teaspoons, fill one with the mixture and then roll the mixture of with the second spoon into a pot of simmering chicken soup. It's my cheaters way of making a gnochi. Use a mix like bisquik instead of flour and you will have a nice potato dumpling.
Take the above mixture and make patties using a couple pieces of plastic wrap. Fry each patty in a non stick skillet until browned on each side in butter. Potato pancakes. Serve with sour cream and dill sauce.
Same mixture as above, lay a good size piece of plastic wrap onto a flat surface, Carefully smear the potato mixture (using the Bisquick) onto the plastic wrap as you would for a jelly roll. Top with whatever your imagination wants. Cheese, ham, onions, left over chili, sour cream and chives, onions and peppers, breakfast sausage, ground beef.... Using the plastic wrap, Lift and roll jelly roll style. Use a sushi roll technique with the plastic wrap. After rolled, use the plastic wrap to lift and place on a sheet pan seam side down. Don't leave the plastic wrap. Brush with melted butter and bake in a pre heated 425* oven for 20-25 minutes or till a nice golden brown. Allow to cool for abot 10 minutes, slice into 1/2" slices and serve with the appropriate condiments.
Left over mashed potatoes make an excellent thickener for stews made in the crock pot.
Freeze leftover mashed potatoes and save for the next time you grill up some stuffed potato skins. Thaw and mix in with the potatoes you scoop out. Mix in your cheese, bacon bits ect. and then fill the skins. Over stuffed is great.
Going with the platic wrap again, Set up for the jelly roll again, mix 1 egg with about a cup or so of mashed potatoes and a tbls of olive oil. You want a mixture like play dough. Season well with salt and pepper. I like a lot of pepper for this and a touch of onion powder. Spread mixture on the plastic wrap, about 1/8" thick. Some like salmon, I like catfish, Place a boneless, skinless fillet on the potato mixture. Using the plastic wrap, fold the potato mixture over the fillet. Use the plastic wrap to mold the potato mixture to the fillet. Pre heat the oven to 425. Place a cast iron skillet in the oven to heat too. Remove the pre heated skillet, Oil well, place the potato crusted fillet into the hot pan and place in the oven and bake until golden brown. About 15 minutes. Flip after 7 minutes caredulllllly. Season with more salt and pepper just before serving. I like this because the potato crust is nice and crunchy. Almost like fish backed into a crispy tater tot. I did a killer dish like this once and blew everyone away by drizzing on a bit of Italian dressing while it was baking.
Fill nail holes made from picture hanging, sand and paint.