Place water and Kaniwa into a 2-quart saucepan; bring to a boil. Reduce heat to a simmer and cover. Cook for 10 to 15 minutes or until all water has been absorbed.
While the Kaniwa is cooking, finely chop the tomatoes, parsley scallions. Add lemon juice, olive oil and fresh mint to the tomato mixture. Stir in cooked Kaniwa and salt. Mix well. Let tabouli sit in the refrigerator for a day to blend flavors.
Tabouli is traditionally served at room temperature so remove from refrigerator 30 to 60 minutes before serving.