Gently brush off any soil from the colocasia roots, then peel them and wipe them with a towel (do not wash). Break the colocasia into small pieces by plunging a knife into the root and snapping it off, rather than cutting. This technique, known as "chakrate", helps maintain the texture.
Peel the potatoes and cut them into quarters, then into small bite-sized pieces, similar in size to the colocasia. Wash the celery and cut it into thick slices. In a large pot, heat the olive oil. When hot, add the onions and sauté until softened. Add the colocasia pieces and sauté for 1-2 minutes. Then, add the potatoes and celery, stirring a few times to combine.
Push the ingredients to the side and add the tomato paste to the bottom of the pot, stirring to release its aroma. Season with salt and pepper, then pour in the hot water and cover the pot. When the mixture comes to a boil, reduce the heat and simmer for 1 hour.
After 1 hour, check the seasoning and add more salt and pepper if needed. Add the lemon juice and cook for another 5-10 minutes, or until the sauce thickens. If the colocasia isn’t fully tender, add a bit more water and continue cooking until softened. Serve warm and enjoy this traditional Cypriot fasting dish.