I have a serious attachment to good mashed potatoes. There are very few leftovers that I feel seriously compelled to see eaten, but mashed potatoes are one of them. They are a comfort food icon and once you decide on a method for cooking them that appeals to you, it becomes difficult to see people serve mediocre mashed potatoes. My mother-in-law would say that all potatoes are good, but some are better than others. I generally agree with that proposition, although I think that there are some grievously bad mashed potatoes to be found at restaurants…even very nice ones.
I am a simpleton when it comes to my mashed potatoes, though. I think simple is the key, in fact. I do want to make colcannon one day soon…but mostly, I like butter, milk, salt and pepper in my mashed potatoes. I do have one “secret” ingredient, however. I always use it, but just a little bit. It adds something to the texture more than the flavor and it is divine. I use a handful of shredded parmesan cheese. In this particular case, having no parmesan on hand, I threw in a handful of Gruyere…hence, the Gruyere topping. But mixing a bit of parmesan or Gruyere into your mashed potatoes lends a subtle bump in texture and flavor that is rather interesting. I’ve had a lot of compliments on mashed potatoes, yet I’ve never had anyone guess that I add cheese to them. That might give you a hint to how little I use relative to say, the heaping piles of butter. My only other “must” is adding the melted butter to the potatoes FIRST. It is a little trick I learned from Cook’s Illustrated at some point and it has served me well. The idea is that you coat the starch molecules with butter before adding the milk and it keeps them from being watery. Whatever the explanation, it seems to work.
So, since I worship at the high holy church of mashed potatoes, I don’t ever want to see them wasted, and that is where cottage pie and shepherd’s pie come into the story. Cottage pie uses beef and shepherd’s pie uses minced lamb. You can also add corn or peas, depending on your preferences, but one of my little friends still doesn’t like visible vegetables cluttering up his food. That is not to say he won’t eat them…he just isn’t a fan of having them all mixed together. This preparation is pure comfort. I keep going back to the dish to have just another little bite. But there is really nothing to it. It is easy. It utilizes precious leftovers (or plan-overs…I think this is worthy of throwing an extra potato or two in the pot).
1 tablespoon canola oil
⅓ cup finely chopped carrot
⅓ cup finely chopped onion
⅓ cup finely chopped mushroom
1½ pound ground beef
1 garlic clove, finely chopped
¼ teaspoon fresh thyme leaves (or dried)
2 tablespoons tomato paste
1 teaspoon Worcestershire sauce
2 tablespoons flour
8 tablespoons water (or use low sodium beef broth)
1 to 2 teaspoons kosher salt
3 cups leftover mashed potatoes
Gruyere cheese (optional)
Heat the oil in a skillet. Add the carrot, onion, and mushrooms and sauté for about 4 minutes or until the vegetables are softened. Add the ground beef to the skillet and mix the vegetables and beef together gently while browning the meat. Using your spatula, continually break the beef into smaller bits. When the beef is almost completely cooked, add the garlic and the thyme and allow them to cook briefly with the meat. Then add the tomato paste and the Worcestershire sauce and stir them completely into the meat. Sprinkle the flour over the meat and mix it in. Add the water to the skillet and allow the meat to simmer for a few moments until it is slightly thickened. This is not intended to be soupy.
Remove the beef from the heat and taste it. Add salt and pepper accordingly. I use about 1½ teaspoons of kosher salt (if you have only table salt, start with ½ teaspoon and work your way up from there. This is how the meat will taste in the final dish, so this is your opportunity to season it. Consider whether your potatoes are particularly salty as you go.
Place the meat into a casserole dish. I used an 8 inch round soufflé dish. Scoop the leftover mashed potatoes on top of the beef and spread it out gently with the bottom side of the spoon. You want about a 2 inch top of mashed potatoes. Place the dish in the oven and bake for 30 minutes.
Remove the dish from the oven and grate a bit of gruyere cheese on top of the mashed potatoes. Let the casserole sit for at least 5 minutes before serving.