This summer dish of thinly sliced poached veal with a creamy tuna sauce is a classic. If you can't find veal, or you want a quicker result, use thin slices of roast beef or turkey. It tastes best when prepared in advance and refrigerated for a few hours before serving
Push the cloves into the onion sections and place them with the veal, vegetables and other aromatics in a medium saucepan (not aluminium or copper). Cover with water. Bring to the boil and simmer for 50-60 minutes. Do not overcook the veal or it will fall apart when sliced. Allow it to cool in its cooking liquid for several hours, or overnight. Reserve the broth for another recipe.
Drain the tuna. Place it in the bowl of a food processor with the capers, anchovies and lemon juice. Process to a creamy paste. If it seems too thick, add 2 or 3 tablespoons of the reserved veal broth and process again.
Turn the tuna purée into a bowl. Fold in the mayonnaise. Taste for seasoning.
Slice the veal as thinly as possible. Spread as little of the tuna sauce onto a serving dish. Arrange a layer of the veal slices on top of the sauce. Cover with a thin layer of sauce. Make another layer or two of veal slices and sauce, ending with the sauce. Garnish with capers and gherkins. Cover and refrigerate until needed. The assembled dish can be kept in the refrigerator for 2-3 days, if necessary.