Dice the onion, carrots and celery.

Deseed and dice the red pepper.

Finely slice the garlic.

Rinse the lentils in a sieve/fine-mesh strainer under cold water.

Heat the olive oil in a large saucepan on a medium heat. Add the onion, carrots, celery, red pepper and garlic and sauté for about 10 minutes until the vegetables are softened.

Add the lentils, sun-dried tomato paste, chopped tomatoes, vegetable stock, dried oregano and smoked paprika to the pan.

Stir well to combine, then turn the heat up to high and bring to the boil. Once boiling, reduce the heat to low-medium, cover with a lid and simmer for about 30–35 minutes, or until the lentils are tender and the mixture has thickened.

Stir in the Worcester sauce, tahini, soy sauce, balsamic vinegar and frozen peas. Season with a pinch of salt and pepper to taste. Set aside.

While the filling is simmering, make the topping. Peel and chop your sweet potatoes into small cubes, about 1.5cm/5⁄8in across. Place the chopped sweet potatoes in a large pot and cover with water.

Cover the pan and bring to the boil on a high heat, then reduce the heat and simmer for about 15–20 minutes, or until the sweet potatoes are tender. You can test them with a fork.

Drain the sweet potatoes and return them to the pot.

Add the olive oil or vegan butter and nutritional yeast. Mash until smooth and creamy.

Season the mashed sweet potatoes with salt and pepper to taste.

Preheat the oven to 200°C/400°F/gas 6. Now assemble the cottage pie.

Spread the lentil and vegetable filling evenly in a large ovenproof dish. Spoon the mashed sweet potatoes over the top of the filling, spreading out evenly.

Bake for about 20–25 minutes, or until the topping is golden brown and the filling is bubbling around the edges.

Enjoy with stir-fried greens or a salad on the side.