Warm the olive oil in a good-sized pan. Chop the onions and finely dice the carrot and mince the garlic. Add to the pot with salt and pepper. Add the grated courgette. Cook on a low to medium heat for 10 minutes until the vegetables are soft. Put the kettle on and make your stock by pouring boiling water over the stock cube. Refill kettle for potatoes.
Add the tomatoes, herbs and lentils, stir for a minute or 2 until everything is coated then pour in the boiling stock. Simmer gently (around 10 mins) until the lentils are soft.
Meanwhile, cut the potatoes into chunks (we don’t peel our white potatoes as we like the texture and added fibre- but do peel the sweet ones). Simmer in a pan of boiling water until tender. Drain and mash with a good knob of butter or olive oil
Check the seasoning of the lentil mixture, you could add some Worcestershire Sauce here if you have it. Pour it into a shallow pie dish and top with the mash. Scatter over grated cheese and slide under a hot grill for 5 minutes until golden and crunchy.
Serve with HP sauce and maybe a side of peas!