Ingredients
1 x 400g tin of green lentils
3 tablespoons tomato purée
1 teaspoon Marmite
1 onion
1 splash of semi-skimmed milk
40g unsalted butter
2kg potatoes
1 teaspoon cumin seeds
3 sprigs of fresh rosemary
olive oil
500g celeriac
500g swede
3 carrots
2 large leeks
10g dried porcini mushrooms