The first step includes the preparation of all ingredients. Use a sharp knife and cut the pitaya in its center. You can use a spoon to pull out its pulp.
Put the pitaya pulp in any bowl. Add juice, eggs, sugar & butter to it. Whisk all of these ingredients. So, they became a smooth and mixed mixture.
Now, take a double boiler and put the above-whisked mixture in it.
Cover it and cook over low heat. It will require only half-hour in its complete making. You have to stir it after a short time continuously. It will start to thicken when you stir it.
Check the taste. If you want more sweetening, you can add more sugar. On the opposite side, you can add more water if you find it too sweet.
After half an hour, check the thick texture of it.
Put this prepared jam in any glass tight jar and close it tightly. It is ready to eat anytime or any day.