Set your Instant Pot to the Sauté function on high. Add the cooking oil. Add in the cubed chunks of chuck.
Brown the beef on all sides. Remove from the pot.
Turn the heat to medium. Deglaze the pot with 1 cup of the coconut milk, scraping up any brown bits. Add 6 tbsp of the curry paste. Let cook or 2 minutes.
Add in the rest of the coconut milk, palm sugar, fish sauce, tamarind paste, and the cooked beef. Put the cover on the Instant Pot. Set the function to Pressure Cooker on high for 30 minutes.
After the 30 minutes is up, release the pressure. Turn the function to Sauté on medium heat. Add in the potatoes, onions, and peanuts. Cook for 10-15 minutes or until the potatoes are cooked through. If the sauce gets to thick, add in a little bit of water.
Serve with steamed rice. Garnish with crushed peanuts and chopped cilantro.