Cook the rice in a pan of boiling salted water for 25 minutes, or until tender, then drain well. Tip back into the pan, finely grate in the lemon zest and squeeze in half the juice, season to taste, then cover.
Peel and finely chop the garlic and ginger, then half, deseed and finely chop the chilli. Peel and finely slice the onion.
Heat 1 tablespoon of oil in a large pan over a medium heat, add the garlic, ginger and chilli, followed by all the spices and fry for 2 minutes to coat.
Pick and roughly chop the coriander leaves (keep to one side), then finely chop and add the stalks to the pan.
Add the onion and cook for a further 6 to 8 minutes, or until softened, adding a splash more of oil, if needed.
Trim and roughly chop the mushrooms and tomatoes. Add the mushrooms to the pan and stir-fry for a few minutes, then add the tomatoes, lentils and 200ml of boiling water. Bring to the boil, cover with a lid and cook over a medium-low heat for around 20 minutes, or until the lentils are tender.
At this stage, remove the lid, turn the heat up to medium-high and leave to bubble away until the sauce thickens and reduces slightly, stirring occasionally.
Stir through the yoghurt, then season to taste with sea salt and black pepper.
Divide the curry and lemony rice between your plates, scatter over the coriander leaves, then tuck in.