Whisk together first 6 ingredients in a large bowl.
Melt 2 Tbsp. butter in a large nonstick skillet over medium heat; add half of egg mixture, and cook, without stirring, until eggs begin to set on bottom. Draw a spatula across bottom of skillet to form large curds. Cook until eggs are thickened but still moist. (Do not stir constantly.) Stir in half of tomato. Remove from heat, and transfer to a warm platter. Repeat procedure with remaining butter, egg mixture, and tomato. Sprinkle whole platter of eggs with chives and parsley; serve hot.