Press the saute function on the Instant Pot and add the olive oil. Once hot, add the onion and garlic. Cook for 2 minutes until the onion softens.
Add the butternut squash, lentils, curry powder, and cumin. Stir for 1 minute to coat everything with the spices.
Pour in the vegetable broth and diced tomatoes. Stir to combine and scrape the bottom of the pot.
Secure the lid and set the valve to sealing. Cook on manual high pressure for 10 minutes.
Allow a natural pressure release for 5 minutes, then quick release any remaining pressure. Open the lid and stir in the coconut milk. Season with salt and pepper.
Ladle into bowls and top with fresh cilantro. Serve with lime wedges on the side.