Lentil Shepherd's Pie with Mushroom Gravy

General Fast With Oil Published August 02, 2026

A shepherd's pie is a gravy problem with potatoes on top. Get the gravy right — dark, thick, savory enough to stand up to a mound of mash — and the rest follows. Lentils and mushrooms give you that depth without stock made from bones.

Brown lentils are correct here; red ones collapse into paste. Cook them until tender but distinct, then let them sit in the gravy while you make the topping so they take on its flavor.

This feeds four generously with leftovers, reheats better than most things, and is the meal to make when someone at the table is skeptical about fasting food.

FASTING LEVEL: Fast With Oil
SERVINGS: 6
TIME: 1 hour 15 minutes

INGREDIENTS

For the topping:
- 1.2kg (2.5 lbs) russet or Yukon gold potatoes, peeled and quartered
- 5 tablespoons olive oil
- 1/2 cup (120ml) hot unsweetened oat or soy milk
- 2 garlic cloves, grated
- Salt and white pepper

For the filling:
- 3 tablespoons olive oil
- 1 large onion, diced
- 3 carrots, diced
- 2 celery stalks, diced
- 300g cremini mushrooms, chopped
- 5 garlic cloves, minced
- 3 tablespoons tomato paste
- 2 tablespoons all-purpose flour
- 1.5 cups (300g) dried brown or green lentils, rinsed
- 4 cups (960ml) vegetable broth
- 3 tablespoons soy sauce
- 1 tablespoon Worcestershire-style sauce or balsamic vinegar
- 2 teaspoons dried thyme
- 2 bay leaves
- 1 cup (150g) frozen peas
- Salt and black pepper

METHOD

1. Heat the oven to 400°F (200°C).

2. Boil the potatoes in well-salted water 20 minutes until a knife slides through easily. Drain and let them steam dry in the colander for 2 minutes — dry potatoes make fluffy mash.

3. Mash with the olive oil, hot plant milk, and grated garlic. Season hard with salt and white pepper. Set aside.

4. Meanwhile, heat the oil in a wide oven-safe skillet or Dutch oven over medium. Add the onion, carrot, and celery and cook 10 minutes until softened.

5. Add the mushrooms and cook 8 minutes until browned and the pan is dry. Add the garlic and cook 1 minute.

6. Stir in the tomato paste and cook 2 minutes, then sprinkle over the flour and cook 1 minute more, stirring constantly.

7. Add the lentils, broth, soy sauce, Worcestershire or balsamic, thyme, and bay leaves. Bring to a boil, then simmer uncovered 30-35 minutes, stirring occasionally, until the lentils are tender and the gravy is thick. It should mound on a spoon, not run.

8. Remove the bay leaves, stir in the peas, and taste for salt.

9. Spread the mash over the filling and rough up the surface with a fork — those ridges are what brown. Bake 25 minutes until golden and bubbling at the edges. Rest 10 minutes before serving.

NOTES

- For strict no-oil days: mash the potatoes with their cooking water and a little plant milk, and build the filling with broth instead of oil. Skip the flour and mash a ladle of the lentils to thicken instead.
- A layer of wilted spinach between filling and mash is a good addition.
- Sweet potato mash works and pairs well with the thyme.
- Assemble a day ahead and bake from cold, adding 15 minutes.