Set the Instant Pot to saute mode and heat the oil. Add the cumin seeds and let them sizzle for 30 seconds.
Stir in the chopped onion, garlic, and ginger. Cook for 3 minutes until the onion softens.
Add the garam masala and turmeric. Stir for 1 minute to toast the spices.
Place the lamb pieces in the pot and brown them on all sides, about 5 minutes total.
Mix in the chopped tomatoes, yogurt, salt, and beef broth. Scrape the bottom to loosen any browned bits.
Cancel saute mode, secure the lid, and set to pressure cook on high for 35 minutes.
Allow a natural pressure release for 10 minutes, then quick release any remaining pressure.
Open the lid and stir the stew. Garnish with chopped cilantro before serving.