Set your instant pot on sear/sauté on medium-high and add 1/4 cup of vegetable oil.
Cut your 1/2 onion into thin slices, about 2 inches long and add them to the pot. Fry until they start to turn golden brown, then take out half of them and set aside for later.
Take your beef and sear it on high heat for a few minutes on each side with the remaining onions. Sear until you don't see any red and then lower the heat to medium-low.
Mix your 1.5 tablespoons of Nihari masala and 1 cup of water in a separate bowl. Pour this mix into the instant pot and stir.
Cover your instant pot and pressure cook on high for 40 minutes with a 10 minute natural release.
In a separate bowl, add 2 tablespoons of all-purpose flour and 1 cup of water. Whisk very well until there are no clumps.
Set your instant pot back to sear/sauté on medium-high heat. Slowly pour the flour mixture into the instant pot, stirring as you go.
Once all of the flour is added, stir in ½ teaspoon of ginger paste or 1 teaspoon minced ginger, 1 tablespoon of chopped cilantro, and your four hard boiled eggs if you are using them. Allow it to simmer for an additional 10 minutes uncovered. Once the desired sauce consistency is reached, reduce to low heat and cover until ready to serve.
Add a generous amount of salted butter to a pan and heat your naan on medium heat.
Top this with some of the remaining cilantro, julienned ginger, the remainder of the fried onions, and lime wedges to squeeze on top. Enjoy!