Add the oil to a 3.5 quart pot and heat over medium heat. Add the curry paste and turn to medium-low heat. Cook and stir until the moisture is reduced and the paste begins to caramelize, 8 minutes or so.
Add the cardamom pod, cloves, and star anise pods. Cook and stir for 1 minute to release the fragrance.
Add the beef and the leftover upper portions of the lemongrass stalks. Turn to medium heat. Cook and stir for 1 minute, until the beef is evenly coated.
Add the coconut milk and soaked tamarind water (do not add the leftover tamarind chunks). Bring to a simmer. Reduce to low or very low heat, whichever is enough to maintain the very low simmer. Add the toasted shredded coconut, kaffir lime leaves, brown sugar, and salt. Stir a few times to mix well.
Cover the pot but leave a small gap about the width of your finger. Cook, stirring occasionally, until the beef turns very tender. The process can take anywhere from 2 to 3.5 hours. When the braising liquid starts to turn golden brown, check on the pot more often, every 15 minutes or so, and stir and scrape the bottom to prevent burning. At the end of cooking, the curry will turn golden brown and the oil will separate. Depending on the cut you use, it might end up with a lot of oil. You can skim the oil with a spoon and discard it before serving. Taste the beef and the curry. Adjust the seasoning by adding salt, if needed.
Serve hot over steamed rice as a main dish or use the meat for meal-prep.
The beef rendang can be stored in the fridge for 4 to 5 days in an airtight container, or in the freezer for up to a month.