Prepare hollandaise sauce according to instructions on package. Set aside and keep warm.
Pour vinegar into a small saucepan filled with water and heat until water starts to simmer. Gently break eggs into water and cook 3 or 4 minutes, making sure water continues to simmer. Remove eggs carefully from pan and dab with a paper towel to absorb water.
Slice flatbread into two and toast each half in toaster. Place 1 slice of ham and 2 eggs on each slice. Top with hollandaise sauce and sprinkle with maple fleur de sel.