Put three glass of water into a bowl and add freshly squeezed lemon juice into it. (it will be used to prevent chopped celeriac and chopped quince pieces to get darken)
Remove the celery parsley from the celery top and wash them and set aside to use garnishing at the end.
Peel the celeriac and chop into approximately 4cm (1.5 inches) pieces. And put them into lemon and water mix and set aside.
Pour extra virgin olive oil into the pot and put carrot, shallot onions and then stir for about 3 minutes.
Add the freshly squeezed orange juice, freshly squeezed mandarin juice, and 2 sugar cubes into the pot and bring the heat to the medium level. Close the lid and let the mix cook 20 minutes more after it boiled.
Take out the chopped celeriac pieces from the bowl of water-lemon juice mix and add them to the pot. Stir them well and then close the lid and cook 20 minutes.
While the celeriac and other ingredients are cooking, peel the quince and chop them into the same size as celeriac, and then put them into the same bowl of water-lemon juice mix.
After 20 minutes passed, take out the chopped quince pieces from the bowl of water-lemon juice mix and add them to the pot. Stir them well and then close the lid and cook 15 minutes.
Take the pot from the heat and set aside. Let it cool down to room temperature.
Serve.
Tip: Garnish with Celery Parsley.