Make several cuts in the wieners, and pan fry well.
Allow the frying pan to cool a bit, then in the residual heat, add ketchup and sauce and coat well.
Story Behind this Recipe
Our bentos always have these in them.
Be sure to make the cuts in the wieners. The sauce will coat them well. If the frying pan is too hot when you add the ketchup, it will evaporate and not coat well. If they are too watery, turn up the heat slightly.