Add the oil to the instant pot and set to saute. When the oil is hot put the cumin and mustard seeds into the oil and fry for around 1 minute.
Add the garlic, chili and turmeric. Season to taste.
Now add the lentils and boiling water.
Put a tall trivet in the instant pot and add the rinsed rice, salt and cold water in a bowl which will fit below the pot lid (you can omit this step and cook the rice traditionally if desired).
Put the lid on the instant pot and set on high pressure for 9 minutes. Leave under pressure for a further 9 minutes and then do a quick release.
Remove the lid and the trivet with the cooked rice.
Stir through the spinach and garam masala. Put the lid back on and leave until the spinach wilts (around 2 minutes).
Serve with the rice garnished with fresh coriander.