Shepherd's pie is one of those exotic-seeming recipes that no one makes, but is actually super easy to throw together, kind of. I make it with beef (which makes it a "cottage pie), because it's easier and cheaper, but "real" Shepherd's Pie is made with lamb. Or you can make "Shepherdess Pie," which is made with beans and vegetables.
I remember discovering shepherd's pie; I was hanging out at this English bar on Greenville Avenue a lot. My friend Smelly and I used to go there on Wednesdays to have a few beers (me) or a few Pimm's Cups (Smelly) and have pub food. I normally ordered bangers and mash, but Smelly has an English uncle who made shepherd's pie for her growing up, so she would order that sometimes. Then we would play loads of Tom Jones songs on the jukebox and flirt with the bartenders. (Just kidding, honey! I never did. It was Smelly.)
Anyhoo. To the cooking part. If you have leftover mashed potatoes, use those. You could probably even make this with instant mashers if you're in a real time crunch.
And don't feel like you HAVE to use what's here. I've made them with corn, without peas, with celery, without mushrooms... use what you like. Also, substitute other potatoes if you want. And leave the skins on the potatoes, or peel them. Do what you like!
1 1/2 pounds Yukon Gold potatoes, cut into 1-inch pieces
1/3 cup milk, or as needed
1/4 cup butter, or as needed
1 tablespoon vegetable oil or butter
1 onion, chopped
2 cloves garlic, chopped
4 carrots, chopped
1 cup sliced mushrooms
Leaves from 4 sprigs fresh thyme (or 1/4 teaspoon dried thyme)
1 pound ground beef
2/3 cup frozen green peas
1 cup chicken or beef stock
1/4 cup flour
Salt and pepper
Heat the oven to 375°F.
Place the potatoes in a saucepot. Add water to cover and a generous pinch of salt. Heat to boiling, then reduce the heat to a simmer and simmer until fork-tender, about 15 minutes. Drain and return to the saucepot. Whisk in the milk and butter and mash until smooth (or use an electric mixer).
Meanwhile, in a skillet, heat the oil then add the onion, garlic, carrots, and thyme. Saute until fragrant then add the mushrooms, and and saute until starting to soften, about 5 minutes. Add the beef, season with salt and pepper, and cook until the beef is browned. Add the peas and cook until heated through. Add the stock, then sprinkle with flour and stir until the liquid has thickened, about 6 minutes.
Spoon the meat mixture into a baking dish and spread into an even layer. Spoon the potatoes over the meat, spreading it into the edges. Use the back of a spoon to make swirls, or use the tines of a fork to make a crosshatch pattern.
Bake until the the potatoes are golden and browned in spots, 25 to 30 minutes. Let stand 10 minutes before serving.