Instant Pot® Braised Beef Short Ribs with Lentils

Turn on a multi-functional pressure cooker (such as Instant Pot®), add olive oil, and select Saute function. Add ribs to the hot oil and cook until browned on all sides, 5 to 7 minutes. Transfer ribs to a plate. Add onion, 1/3 of the celery, and garlic to the pot; cook and stir until onion is translucent, about 5 minutes. Cancel Saute function.

Place a trivet in the pot and lay ribs on top; season with salt and pepper. Pour in 1 cup beef broth and close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 45 minutes. Allow 10 to 15 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions, 10 to 40 minutes.

Transfer ribs to a cutting board and remove any remaining fat. Shred the meat and return it to the pot, along with the bones.

Cover meat with lentils, mushrooms, carrots, and remaining celery; stir to combine. Pour in remaining beef broth and water until 1/2 inch higher than food. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 20 minutes. Allow 10 to 15 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions, 10 to 40 minutes.

Remove and discard bones before serving.