Step 1

Heat the oil in a saute pan, oven a medium heat. Add the onions, garlic, carrots and celery and fry for 5 minutes.

Step 2

Add the mushrooms in for another 5 minutes.

Step 3

Add the flour, thyme, rosemary, pepper and fry for 3-5 minutes until everything is well coated.

Step 4

Add in the lentils, tomato purée, stock, Marmite and Henderson's Relish. Cook for 30 minutes until the sauce is rich and thick.

Step 5

Meanwhile, boil up the potatoes until soft enough to mash. Mash with butter and salt and pepper.

Step 6

Top the base with the mash potato, then smooth over with the back of a fork to create grooves. Bake at 200C for 20-25 minutes until golden and crispy.