Crack eggs into medium mixing bowl, then whisk with a fork until well blended.
Add the tomato, red onion, cilantro, jalapeƱo, cayenne and turmeric and stir to incorporate. Season lightly with salt and pepper.
Melt half the butter in a small nonstick pan over medium high heat. Pour in half of the egg mixture; cook for about 1 to 2 minutes, until the omelet is almost cooked through and you can slide a spatula underneath. Flip as you would a pancake and cook for a few more seconds. Light browning is okay.
Repeat with the remaining butter and egg mixture.
Serve right away on buttered toast with ketchup, if desired.