In a large pot bring the water to a boil.

Add the chopped potatoes and boil until potatoes can be easily poked with a fork, about 10-15 minutes. Remove from heat, drain off excess water and return potatoes to the pot.

Add in butter, heavy cream, and salt. Using a hand mixer with the beater attachments, or a potato masher, mix/mash the potatoes until they are a smooth creamy consistency. Set aside.

Preheat oven to 350°F.

In a large cast iron (or oven safe skillet)* over medium heat, add the vegetable oil and ground turkey to the skillet. Cook until turkey is fully cooked and browned.

When the turkey is fully cooked, add the frozen peas, corn, red onion, lentils, and gravy, then stir to combine. Transfer back to the stove and heat the turkey mixture for an additional 5 minutes over medium-low heat.

Remove from the heat and using a spatula, smooth out the top of the turkey filling. Scoop the prepared mashed potatoes on top and evenly spread over entire pan.

Bake the shepards pie for 30 minutes. At the end of the baking time, switch the oven to broil (high), and broil for 5 more minutes.

Let cool slightly before serving.