Lentil & Vegetable Hotpot

Halve, peel and chop the onion into small pieces. Trim the carrot (no need to peel!), quarter lengthways, then chop widthways into small pieces. Halve, then remove the core and seeds from the pepper and chop into small pieces. Roughly chop the mushrooms. Drain and rinse the lentils in a sieve. Roughly chop the parsley (stalks and all).

Heat a splash of oil in a large saucepan over medium heat. Add the onion and carrot and cook, stirring occasionally, until slightly soft, 4-5 mins. Add the pepper and mushrooms, along with a pinch of salt and pepper. Cook, stirring, until soft, 5 mins.

Next, add the lentils, Provençal herbs and tomato purée to the pan and stir well. Pour in the water (see ingredients for amount) along with the stock powder. Add the mustard (see ingredients for amount - add less if you don't like heat!), then stir in the spinach a handful at a time until wilted. Simmer for a minute then add half of the parsley.

Transfer the lentil mixture from the pan into an ovenproof dish. Once the potatoes are cool enough to handle, arrange on top of the pie, overlapping each slice of potato (see photo). Season with a few grinds of black pepper. Grate the cheese on top then bake on the top shelf of your oven until bubbling and golden, 10-15 mins.