I don't know if you would be up for making your own, but I regularly make a similar dish using a pork loin, flavored in the manner of porchetta, cooking until barely pink, let cool, slice and serve with Tonatto sauce. Works great, and easy and less expensive to aquire a good pork roast. The tuna sauce is so piquant and flavorful, that I don't notice I am not eating veal. My french BF loves it as well. Nice on a warm evening with a salad and white wine.