Step 1

Preheat oven to 350 degrees F.

Step 2

Start the potatoes to boil (see note below) and then continue with the rest of the recipe. In the pan the potatoes were cooked in, while potatoes are still hot, mash the potatoes. Add 2 tablespoons butter and the milk and continue to mash. Add salt and pepper. The mash should be stiff and heavy but a texture that’s spreadable. Add a little more milk if needed. Cover to keep warm while the rest of the dish is assembled.

Step 3

In a 10-inch ovenproof skillet, heat the three tablespoons butter over medium heat. Add the onions, celery, and carrots, and stir. Continue to cook, stirring often, until softened, about 8 to 10 minutes.

Step 4

Sprinkle with the amount of flour needed to make the amount of gravy you need. Stir for about 2 minutes until flour begins to appear dry and incorporated. Add the amount of broth you need and stir, bring to a simmer and cook several minutes until thick enough to coat the back of a spoon. Add any additional leftover gravy and heat through. Taste and add Worcestershire sauce, a splash of wine, salt, and pepper to taste.

Step 5

Gently stir in leftover pot roast, sprinkle with peas, top with mashed potatoes. Make the top attractive with swirls or with a crosshatch done with a fork. Brush with the melted butter and place in oven to heat through, about 20 minutes. It’s ready when hot; the gravy will probably be bubbling up around the edges of the pan. If the top isn’t browned to your satisfaction, turn on broiler and watch carefully. It usually takes three or four minutes.

Step 6

Remove from oven and serve immediately.

Step 7

To cook potatoes: Peel the potatoes and cut into 1/2-inch dice. Place in a medium saucepan and cover with cold water. Set over high heat, cover and bring to a boil. Once boiling, uncover, decrease the heat to maintain a simmer and cook until tender and easily crushed about 10 to 15 minutes. Drain and return to the pot to keep warm.

Step 8

If you don’t have an ovenproof skillet, the ingredients for Shepherd’s pie can be transferred, after cooking, to a casserole and then topped with the potatoes.