Tip the lentils into a pan. Pour enough cold water into the pan to cover the lentils. Leave them to soak while you prepare the veg.
Peel and grate the garlic and ginger. Finely slice the mushrooms. Rinse the rice in a sieve under cold water for 1 min, then set aside to drain.
Warm a small pan over a medium heat. Add ½ tbsp oil and the mushrooms. Season with salt and pepper. Stir and fry for 8-10 mins till browned and juicy. Add the rice and 300ml boiling water. Cover. Simmer over a very low heat for 20-25 mins till all the water has been absorbed. When the rice has absorbed all the water, take off the heat. Set aside, lid on, for 5 mins to finish cooking.
Meanwhile, drain the lentils and leave them in the sieve. Warm ½ tbsp oil in the empty lentil pan. Add half the ginger and garlic, 1 tsp turmeric and ½ tsp chilli powder. Stir and fry for 30 secs. Add the soaked lentils and 450ml boiling water.
Season with a good pinch of salt and pepper. Pop the lid on the pan. Bring to the boil. Turn the heat down. Cover. Simmer for 10-15 mins till the lentils are soft and thick but still a little soupy. Keep your eye on the pan. Stir every so often so they don’t catch and burn. Add more water if the lentils need it. This is your daal.
While the lentils simmer, peel and slice the onion. Warm ½ tbsp oil in a frying pan over a medium heat. Add the sliced onion. Stir and fry for 8-10 mins till golden.
Add the rest of the garlic and ginger to the onion with 1 tsp each of the cumin and fennel seeds and ½ tsp chilli powder. Stir and fry for 1 min. Take off the heat.
Stir the spinach into the cooked mushroom rice so it wilts. Serve the rice with the daal, topped with the spiced fried onions.