Pasta with Asparagus and Arugula-Pistachio Pesto

Ingredients

• 2 cups packed arugula (2 1/2 oz.)
• 1 cup raw unsalted pistachios
• 2 medium cloves garlic, coarsely chopped
• 3/4 cup plus 2 Tablespoons olive oil
• 1/2 cup finely grated Parmigiano-Reggiano
• 1/2 teaspoon kosher salt
• 1 small yellow onion, finely chopped
• 1 1b. dried acini de pepe pasta
• 4 cups low-sodium chicken or vegetable broth
• 1/2 cup water
• 1 1b. asparagus, trimmed and cut into 1-inch pieces (3 cups)
• 1 lemon, zested and juiced
• Lemon wedges for garnish
• Crushed red pepper flakes, for garnish