Vitello Tonnato Burger Recipe

Name: Vitello Tonnato Burger Recipe
Ingredients: 1 1/2 pounds best-quality ground veal; 1 shallot, finely diced; 2 ounces capers, rinsed and coarsely chopped; zest of 1 lemon; a handful of flat-leaf parsley, finely chopped; drizzle of olive oil; sea salt and black pepper; 4 ciabatta rolls halved; 1 bunch watercress, washed; 2 egg yolks; 2 tablespoons lemon juice; 5 salted anchovy fillets, finely chopped; 3/4 cup olive oil; 7 ounces canned sustainable tuna in olive oil, drained; 1 tablespoon salted capers, rinsed; splash of white wine vinegar; squeeze of lemon juice; 3 tablespoons olive oil; 2 tablespoons capers, rinsed and dried