For the confit, peel and finely dice the onions. Heat 4 tablespoons of oil in a frying pan. Fry the onions over a low heat for about 10 minutes while turning them over. Season with salt and pepper. Stir in honey. Let the confit cool down.
Cut the gherkins into fine strips. Clean, wash and coarsely chop the arugula. Wash the tomatoes, halve or quarter them depending on size. Cut the boiled beef first into thin slices and then into fine strips.
For the vinaigrette, mix vinegar, salt, pepper and 1 pinch of sugar. Fold in 8 tablespoons of oil. Mix the meat, tomatoes, gherkins, rocket and vinaigrette. Divide the onion confit into twelve glasses. Arrange the boiled beef salad on top.