Watercress and Pistachio Pesto

Ingredients

• • 6 cups (1.5 litres) packed watercress (2 bunches)
  • 1/2 cup (125 ml) pistachios, toasted
  • 1/2 cup (125 ml) grated Parmigiano-Reggiano cheese
  • 4 teaspoons (20 ml) lemon juice
  • 2 cloves garlic, peeled 

  • 1/2 cup (125 ml) canola oil, approximately
  • Salt and pepper