Beef: Season the beef with a good pinch of salt and pepper. Heat the coconut oil in the instant pot on the saute setting. Add ½ the meat and brown on all sides, about 2-3 minutes total. Remove meat to a plate and repeat with the second batch and remove when done.
Curry: Add the onions and push them around so that they pick up any browned bits left behind by the beef, about 1 minute. Add the potatoes, beef, and the curry paste. Stir everything so that the paste is evenly distributed among the beef and potatoes. Add the coconut milk, broth, bay leaves, sugar, fish sauce, tamarind paste, and crushed peanuts. Cover the instant pot, hit the manual button and set it for 30 minutes. Allow the pressure to release naturally before removing the lid.
Serve: taste curry for seasonings and adjust with salt as desired. If you want it to be tangier, you can dilute a little more of the tamarind with a tablespoon of water and stir it into the curry. Serve with jasmine rice or noodles.
Notes
if you decide to use store-boughtcurry paste, you'll need to play around with the amount as I'm unsure how much you'll end up needing.
I haven't tried making this curry on the stove so not sure how you'd go about doing that just yet. I'd think it would require at least 2 ½ -3 hours of low and slow simmering and would certainly need a lot more like 1 ½ cups of beef broth or something along that line.