1. Spread one slice of bread with peanut butter.
2. Spread peanut butter with mayonnaise.
3. Top with mustard.
4. Cover with another slice of bread and slice in half.

Cook's Comments :
Dad's words of wisdom: "Mayonnaise keeps the peanut butter from sticking to the roof of your mouth. This tastes pretty bad, so you use mustard to kill the taste!"