The finished recipe. Lentil Shepherd's PieIngredients 1 to 6. Two tins, drained (600 g) Cooked lentils (Cooked weight, green or brown. A pouch is already this.). 900 g Potato (Floury potatoes. Waxy ones make a gluey mash. Raw, peeled weight.). 150 g Onion. 200 g Carrot. 150 g Mushrooms. 150 g Frozen peasIngredients 7 to 11. 40 g Tomato purée. 300 g Vegetable stock (Made up from a cube or a pot.). 1 tbsp (15 g) Balsamic vinegar. 20 g Olive oil (Half into the filling, half beaten into the mash.). A few sprigs Fresh thymeStep 1. Boil the peeled, chunked potatoes in salted water for 20 minutes until tender. Drain, steam dry for a minute and mash with 10 g of the oil, salt and a splash of the cooking water.Step 2. Meanwhile cook the chopped onion, carrot and mushrooms in the other 10 g of oil for ten minutes, then add the purée, thyme, lentils, stock and vinegar. Simmer for 15 minutes until thick, then stir in the peas.Step 3. Tip the filling into a baking dish, spread the mash over and rough the top with a fork.Step 4. Bake at 200°C for 30 minutes until the top is browned at the ridges.