For thick yogurt remove the yogurt in a strainer or a muslin cloth and let it strain for 2 hours at least or alternatively one can use Greek yogurt or cheese or mayonnaise
Mix all the remaining ingredients excluding bread slices.
Apply butter on all the slices on one side.
Layer the mixture equally among 2 slices of bread.
Cover it with another slice of bread.
You can enjoy this as is or toast them in a toaster or a pan.
Cut and serve.