Boil water in a saucepan. Add the vinegar. Put some ice cubes into a bowl of cold water. Break each egg into separate bowls. Pour one egg very gently into the boiling water, while turning the bowl. Do the same with the other eggs. Let them cook for 2 ½ to 3 minutes.
Using a slotted spoon, lift the eggs out of the water and check them by touching them with your fingertip; you should feel alittle resistance. When they are done, place them in the ice water.
Make the Beaujolais Sauce
Mix the egg yolk with the salt and mustard. Add the oils, alittle at a time, whisking constantly, to make a mayonnaise.
Prepare the Bread
Cut four circular croutons out of the slices of bread, using a 2-inch (5-cm) cutter. Remove the crusts from the rest of the bread and discard them. Dice the remaining bread. Heat the oil in a frying pan. Cook the croutons and the bread dice for a few seconds on each side, until golden brown.
Finish the Sauce
Rinse out the frying pan. Pour in two-thirds of the Beaujolais and add the sugar. Reduce to a syrupy consistency.
Transfer to a small bowl. Gradually work this reduction into the mayonnaise. Add the red wine vinegar and mix. Add the rest of the wine. Mix again.
Drain the eggs, then trim* them: Cut off any trailing parts of the white.
Rinse the parsley and chervil, shake them dry, and pull off the leaves. Chop them finely with a knife. Place the croutons in the middle of four deep plates or four egg-plates. Carefully lay an egg on each crouton.
Coat with 1tablespoon of Beaujolais sauce. Garnish with bread dice and chopped herbs. Surround with a thread of olive oil and finish off with a twist of pepper.