Cut the potatoes into chunk cubes and cook them in boiling water and put them aside.
Turn the stove on medium-high then add ½ can of lite coconut milk,1 cup of water, 1 tablespoon of Masaman curry paste, and beef into a pot. Simmer the beef and the other ingredients for 30 to 45 minutes or until the meat is soft and tender then put it aside.
Turn the stove on high. In a large pot, add olive oil and 3 tablespoon Masaman curry paste. Stir-fry the paste until you can smell the paste's aroma then add one can of lite coconut milk. Once the curry is boiling, add more lite coconut milk a bit by bit. So basically, every time that the curry is boiling, you are going to more of the coconut milk (all the rest of the coconut milk).
Add the cooked beef and potatoes, cinnamon sticks, bay leaves, ½ cup of water, sweet onion, fish sauce, tamarind, coconut sugar. Mix all the ingredients together and let them cook until the onion is cooked.
Serve the curry with a choice of your steamed rice, but I recommend either jasmine brown rice or basmati rice (these are one of the healthier choices among the other kind of rice) and sliced avocados.