Heat the coconut oil over medium-high heat in a small (5- to 6-inch) skillet. Swirl it
around the pan to coat the bottom entirely.
In a small bowl, whisk together the eggs, parsley, chives, salt, and pepper. Pour the eggs into the skillet and cook, undisturbed, for 1 minute. Arrange the tomato slices on top of the frittata. Pour the teaspoon of water into the pan at the edge of the frittata. Immediately cover the pan with a lid. Reduce heat to low and cook, covered, for 1-2 minutes or until the frittata is slightly puffed and set.