In a food processor, puree the mortadella with all of the ingredients except for the ½ cup of pistachios until the texture is creamy.
Scoop the pâté into a serving bowl, cover and allow to chill in the fridge.
Toast the pistachios on a small cookie sheet at 350° until lightly toasted—about 5 to 10 minutes. (Coat with a little olive oil and salt beforehand, if desired.)
Let the pistachios cool for a few minutes, then toss them across the top of the pâté.
Garnish with the rosemary for color and serve with the crostini and crackers.