Begin by preparing your mashed potatoes. Find our family's favorite mashed potato recipe in the post above.
Preheat your oven to 375°F.
While your potatoes boil, heat a large sauté pan or large cast iron skillet over medium-high heat and add a tablespoon of olive oil.
Add 2 lbs ground beef to the skillet, breaking it up with a wooden spoon as it cooks. Turn the burner down to medium heat.
Once the beef is browned, drain any excess fat.
Optional: Add a splash of beef broth or dry red wine to the meat while sautéing to deglaze the bottom of the pan and enhance the flavor.
Add 1 tsp each of basil, thyme, and garlic powder (or 2 cloves minced garlic) to the beef mixture. Stir well to combine and cook for another 2-3 minutes to allow the flavors to incorporate.
If using a cast iron skillet, you can assemble the shepherd's pie directly in the skillet. If not, transfer the ground beef mixture to the bottom of a large casserole dish, spreading it out evenly.
Add a layer of 5 cups frozen corn over the beef mixture.
Spread a generous layer of creamy mashed potatoes (about 4-5 cups) over the corn, smoothing it out with the back of a spoon. For an extra touch, create small peaks in the potatoes with a fork, which will turn golden brown in the oven.
Place the cast iron skillet or casserole dish in the preheated oven and bake for about 25-30 minutes, or until the top is golden brown and the filling is bubbly.
Allow the shepherd's pie to cool for a few minutes before serving, ensuring the entire dish is set and easy to serve.