Peel onion, cut it in half and add a toothpick thru one half of it to keep it from falling apart in the soup. It will get removed later.
Peel and crush garlic.
In the Instant Pot add the lentils, sweet potatoes, water, the half onion, garlic, cumin, and a pinch of salt. Put the lid on and cook on high for 15 minutes. Do a quick release once it's finished.
While it's cooking, prepare the cilantro oil by putting a big handful of cilantro leaves into the blender along with olive oil. Blend well until all coriander is very small. Scraping might be necessary mid-through.
Once soup is cooked, remove the half onion. Blend the remaining ingredients with an immersion blender or food processor and season to taste with more salt and pepper.
Serve in a bowl with a swirl of coriander oil and freshly ground pepper and fresh bread of your choice.
Notes
Original recipe: https://greenhealthycooking.com/red-lentil-sweet-potato-soup/