Set the Instant Pot to sauté mode and heat the olive oil. Add the onion, garlic, and ginger, then cook for 3 minutes until the onion softens.
Add the lamb cubes and brown them for 4 minutes, stirring occasionally.
Stir in the berbere spice and cook for 1 minute until fragrant.
Pour in the diced tomatoes with their juices, beef broth, lentils, and salt. Stir to combine and scrape the bottom of the pot.
Cancel sauté mode, secure the lid, and set to manual high pressure for 25 minutes.
Allow a 10-minute natural pressure release, then quick release any remaining pressure.
Open the lid and stir the stew. Serve hot, topped with chopped cilantro.