Layer the Shepherd’s pie: Line the baking vessel with the mashed potatoes to resemble a pie crust, then add meat, add pine nuts on top of the meat (optional),then potato on top.
Some people put an egg on top so the top becomes crusty. (beat one egg and then brush it on top) or spray some oil spray on the top and let it brown.
For extra touches: Gently drag the teeth of a fork starting at the rim of your baking dish in concentric circles ending at the center of the dish to create furrows.( like a rock Zen Garden) This will help the top of the pie get crusty and it also looks great. You may also sprinkle some paprika on top before baking.