• Preheat oven to 425°F.

Shepherd's Pie Filling

• Melt the butter in a large, cast iron skillet over medium heat.
  1 tablespoon butter
• Add the onion and carrots and season with a pinch of salt and pepper.
  1 large onion, 1/2 cup carrots, salt, pepper
• Cook, stirring often, until the vegetables begin to softened, about 3 to 5 minutes.
• Add the ground beef and season with salt and pepper. Cook, breaking up with a meat chopper or a spatula, until no longer pink, about 5 minutes.
  salt, 2 pounds lean ground beef, pepper
• Sprinkle on the flour and mix in.
  2 tablespoons all purpose flour
• Stir in the beef stock and raise the heat to bring to a boil. Cook a minute or two to thicken the gravy.
  1 cup beef stock
• Stir in the peas.
  1/2 cup peas
• Remove the skillet from the heat. Spread the filling out evenly in the bottom of the pan. Set aside.

Mashed Potatoes

• While the filling is cooking, add the potatoes to a pot of cold, salted water.
  2 pounds potatoes
• Bring to a boil and cook until the potatoes are fork tender, about 8-10 minutes.
• Drain the potatoes and place in a medium size bowl.
• Return the pot to the stove top over low heat. Add the butter and heavy cream to the pot and warm until the butter is fully melted.
  4 tablespoons butter, 2 tablespoons heavy cream
• Break up the potatoes with a potato masher or a fork.
• Carefully pour in half of the butter mixture and continue to mash the potatoes.
• Gradually add the remaining butter mixture until the desired level of creaminess is achieved.
• Season with salt and pepper to taste.
  salt, pepper
• Dollop the mashed potatoes over the top of the filling in the skillet.
• Spread with the back of a spoon.
• Transfer the skillet to the oven and bake for about 20-25 minutes.
• If a more golden crust is desired, turn on the broiler and place the skillet underneath. Broil, watching very closely, until browned to your liking.