Mix in the frozen peas and cook for another 2-3 minutes until heated through.
Spread the lentil and vegetable mixture evenly in the bottom of a baking dish.
Spoon the mashed potatoes over the lentil filling and spread evenly to cover the surface completely.
Preheat the oven to 375°F (190°C). Bake the assembled shepherd’s pie for 25-30 minutes, or until the top is heated through and lightly golden around the edges.
Notes
For extra creaminess, add a touch of cream or butter to your mashed potatoes before layering them on top.