Classic salad Lyonnaise: a French salad with soldiers (croutons in French), bacon, poached eggs and a simple mustard dressing.
Combine the white wine vinegar, the olive oil and the mustard.
Whisk until you get a nice looking salad dressing. Then season with a little pepper and salt to taste. Put it aside until later. Melt the butter in a non-stick pan over medium heat and add the diced bread. Gently brown the bread until golden and crisp. Stir regularly.