Heat the butter in a skillet, over medium heat, until hot. Turn the heat down to med-low, then add the onion and ginger and cook for approximately 5 minute. Add the chile, cumin and turmeric and then cook for approximately 1 minute, while stirring.
Beat the eggs with the yogurt and 1/2 t salt, lightly. Turn the heat to low and add the eggs to the onion mixture. Cook this all, stirring , until the eggs are just set, approximately 12 minutes.
Stir in the tomatoes, cilantro and salt and pepper, to taste.