Step 1 of 21
Foolproof Savory Shepherd's Pie
Preheat the oven to 425°F.
Step 2 of 21
Foolproof Savory Shepherd's Pie
Spray a 9-inch pie plate with non-stick cooking spray. Set aside.
Step 3 of 21
Foolproof Savory Shepherd's Pie
Peel the potatoes and dice into 1/2-inch cubes.
Step 4 of 21
Foolproof Savory Shepherd's Pie
Place the potatoes in a large pot filled with cold water. Set the pot over high heat and bring to a boil. Boil the potatoes until they can be easily pierced with a fork, 15-18 minutes.
PRO TIP Start the meat filling while the potatoes boil.
Step 5 of 21
Foolproof Savory Shepherd's Pie
Once tender, drain the potatoes in a large colander and return them to the pot. Add the butter, sour cream, salt, and black pepper. Mash the potatoes until smooth. Add milk and stir gently to combine.
PRO TIP If the potatoes seem too thick, add more milk one tablespoon at a time until desired consistency is reached.
Step 6 of 21
Foolproof Savory Shepherd's Pie
Thinly slice the mushrooms.
Step 7 of 21
Foolproof Savory Shepherd's Pie
Finely dice the onion.
Step 8 of 21
Foolproof Savory Shepherd's Pie
Finely dice the carrot
Step 9 of 21
Foolproof Savory Shepherd's Pie
Finely dice the celery.
Step 10 of 21
Foolproof Savory Shepherd's Pie
In an extra-large skillet over medium-high heat, melt the butter. Add mushrooms and salt. Sauté, stirring frequently, until the mushrooms have released their juices and are nicely browned, 5-6 minutes.
Step 11 of 21
Foolproof Savory Shepherd's Pie
Transfer the mushrooms to a bowl and set aside.
Step 12 of 21
Foolproof Savory Shepherd's Pie
Add the olive oil to the pan. When oil shimmers, add the onions, carrots, and celery. Sauté over medium-high heat, stirring frequently, until they are soft and translucent, 7-8 minutes.
Step 13 of 21
Foolproof Savory Shepherd's Pie
Add the lean ground beef, thyme, nutmeg, salt and black pepper to the skillet. Sauté over medium-high heat, breaking beef up as it cooks, until browned and cooked through, 7-8 minutes.
Step 14 of 21
Foolproof Savory Shepherd's Pie
Return mushrooms to skillet. Add the Worcestershire sauce, tomato paste, corn, and peas to the pan. Stir until the corn and peas are thawed, about 2 minutes.
Step 15 of 21
Foolproof Savory Shepherd's Pie
Reduce the heat to medium. Sprinkle the flour over the beef mixture. Cook, stirring constantly to incorporate and toast the flour, about 1 minute.
Step 16 of 21
Foolproof Savory Shepherd's Pie
Slowly stream the beef broth into the pan. Cook, stirring frequently, until broth begins to bubble and thicken, about 2 minutes.
Step 17 of 21
Foolproof Savory Shepherd's Pie
Remove the skillet from the heat. Transfer the beef mixture to the prepared pie plate and smooth into an even layer.
Step 18 of 21
Foolproof Savory Shepherd's Pie
Spoon the potatoes over the beef mixture, spreading them all the way to the edge. Use the back of the spoon to make small peaks in the potatoes.
Step 19 of 21
Foolproof Savory Shepherd's Pie
Place the pie plate on a large baking sheet. Bake the pie on middle rack of oven until potatoes are lightly golden and the edges are bubbling, 15-17 minutes.
Step 20 of 21
Foolproof Savory Shepherd's Pie
Check to see that pie is done. Remove from oven or add time as needed.
Step 21 of 21
Foolproof Savory Shepherd's Pie
Allow to rest for 7-10 minutes before serving. Refrigerate leftovers for up to 3 days.