Cut the beef into 2-inch (5-cm) chunks and season with the salt.
In a large, heavy-bottomed pot, add the oil and place over medium-high heat.
Add the beef pieces to the pot and brown on all sides, working in batches if needed to avoid crowding and to get a good sear.
Add the lemongrass, kaffir lime leaves, galanga and garlic.
Add the stock or water to the height of the beef pieces.
Bring the mixture to a boil, then reduce the heat to a simmer for about 45 minutes, covered, or until the beef begins to become tender.
Set aside, reserving the cooking liquid.
Heat a wide, deep skillet over medium-high heat for about 1 minute.
Stir in 3 to 5 tablespoons (45 to 75 ml) of the thick coconut cream, along with the curry paste, bay leaves and shrimp paste.
Stir-fry for about 3 minutes, until the paste starts to brown and stick to the pan and is very fragrant.
If it seems dry or starts to sputter, add a little coconut milk to keep it moving.
Take care not to burn the paste and spices.
The paste should look like it’s frying, with oil separating out from the paste.
Stir the remaining coconut milk into the curry paste.
Scrape the bottom of the pan to release and deglaze anything that may be stuck.
Increase the heat to high and bring the sauce to a boil.
Allow the mixture to boil, uncovered, for 5 to 10 minutes or until the sauce reduces by about a quarter and coats the back of a spoon.
Reduce the heat to a simmer.
Add the cooked beef pieces, fish sauce, tamarind concentrate and sugar.
Add the potato pieces and onion.
Let simmer, loosely covered, for about 30 minutes, or until the beef and potatoes are tender.
Add some of the reserved beef cooking liquid if the curry gets too thick.
Taste and adjust any of the seasonings (fish sauce, tamarind concentrate and sugar) if you’d like and discard the bay leaves.
Serve with steamed jasmine rice and garnish with the peanuts.