Pistachio Parmesan Crostini

Name: Pistachio Parmesan Crostini
Ingredients: 1 loaf seeded sourdough baguette, sliced on the diagonal 1/2 thick; 6 tablespoons unsalted butter, room temperature; 1/4 cup parmesan cheese, grated; 1/2 cup pistachios, shelled and finely chopped; 2 teaspoons black pepper, freshly cracked; 1/3 cup Good quality olive oil for garnish