Clean the beef and cut it into bite-sized pieces. Let it drain. Peel the carrots, cut them into flower shapes, and slice them into 1/2-inch thick rounds. Cut the onion into wedges. Smash the lemongrass and cut it into sections. Mince the garlic. Mix the cornstarch with 2 tablespoons of water. Prepare the fresh coconuts by cutting the tops off.

Heat a stew pot with a little oil, add the garlic and lemongrass, and sauté until fragrant. Turn off the heat, add the beef, ketchup, and beef stew seasoning packet, and mix well. Marinate the mixture for 1 hour to absorb the flavors.

After 1 hour, place the stew pot on the stove, turn on the heat, and add the fresh coconut water. Cover tightly. Bring to a boil. When the pressure cooker whistles, turn off the heat and let it rest for 15 minutes. Then turn the heat back on, following the same process as before.