lemon pistachio linguini

lemon pistachio linguini, originally uploaded by ulrika_kjarval.
ingredients:

Ingredients:

• 1 pound thin linguini
• 1 stick butter
• 1 tablespoon all-purpose flour
• 1/2 cup milk
• 1/2 cup vegetable or chicken stock
• 2 tablespoons lemon zest (2 large lemons)
• juice of one lemon
• 1/2 cup roughly chopped pistachios
• 1 cup grated parmigiano-reggiano