Crispy Prosciutto Tartines With Whipped Feta And Pistachio Pesto

Ingredients

• 1 (12 ounce) block feta cheese
• 1/4 cup sour cream, at room temperature
• 4 ounces cream cheese, at room temperature
• 3 tablespoons extra-virgin olive oil
• Kosher salt, as needed
• Black peppercorns, freshly ground, to taste
• 4 cups fresh basil, loosely packed
• 1/2 cup parmesan, freshly grated
• 4 cloves garlic
• 2/3 cup pistachios, shelled and lightly toasted
• 1/2 cup olive oil
• Kosher salt, as needed
• Black peppercorns, freshly ground, as needed
• 2 lemons, zested and juiced, divided