When you visit Piedmont in Italy virtually every restaurant serves Vitello Tonnato.
In summer it is a popular main course dish or it is served as an antipasto course.

The view from this charming restaurant on a hill in Piedmont near Barollo
I am not enthusiastic about mixing meat and seafood but somehow this dish has always appealed to me. It works because the rich tuna mayonnaise topping covers thin slivers of poached veal, which is lean and has a very mild flavour.
It’s really the delicious tuna mayonnaise that does it for me, so I often vary the dish by using it as a topping for eggs, wilted spinach or baby potatoes. In some cases I ‘dilute’ the mayo with some Greek yoghurt to make it less rich!

Salad with a Tonnato dressing diluted with yoghurt
Here are some photos of the ‘real thing’ in Piedmont.
Note the thick yellow mayo. In Italy you can buy eggs with extra golden yolks for pasta and mayo. I’m sure the chickens are fed plenty yellow maize and grated carrots!
The dish takes a while to prepare, but the advantage is that it must be prepared at least a day in advance and it actually benefits from at least two days in advance.
Veal is difficult to source in South Africa so I either use pork or beef. You can use a pork loin, trimmed of the fat, but I usually use pork fillets. If you are using beef, ask the butcher for the eye muscle of the silverside (often used for pickled or corned meat). You marinate the meat for at least 12 hours in a mixture of white wine, onions, garlic, bay leaves and peppercorns. Then the meat is traditionally simmered in the liquid for 60-90 minutes depending on the cut and thickness. I cook it covered in the oven. This is gentler and the meat is tenderer.
The meat is left to cool in the cooking liquid and is refrigerated for at least 12 hours before use.
The tuna mayonnaise can be made by making a home-made mayo, blended with tuna, anchovies and seasoning. You may cheat by using a good quality prepared mayonnaise, but I assure you once you have tasted ‘the real thing’ it is worth the effort. Traditional recipes use hard-boiled egg yolks in the mayo, but I use my usual recipe using raw yolks.
In this recipe you need to use the tuna preserved in oil. In Italy it is sold in glass jars. You use the oil as it imparts flavour and richness.
To assemble the dish the meat is sliced very thinly, 3-4mm being ideal. The slices are arranged in a single layer on a platter and then the tuna mayonnaise is spooned and lightly spread over the meat, leaving the edges of the meat visible. To finish the dish it is sprinkled generously with capers. To add a little colour you may sprinkle some finely chopped Italian parsley over, but this is seldom applied in Piedmont.
The assembled dish can also be prepared a few hours in advance and refrigerated until enjoyed.
Serve it with crusty Chiabata or Italian breadsticks