Whole-Wheat Spaghetti with Meyer Lemon, Arugula, and Pistachios

INGREDIENTS

• 1/2 cup shelled unsalted pistachios
• Sea salt or coarse salt
• 1 small shallot, cut into eighths
• 1 Meyer lemon (about 5 ounces), cut into eighths and seeded
• 3 tablespoons lemon or regular extra-virgin olive oil
• 1/2 pound whole-wheat spaghetti
• 2 cups packed baby arugula
• Freshly ground pepper