Gjusta's Green Harissa

Ingredients

½ onion, halved1 tomatillo, husk removed, rinsed1 jalapeño, halved, seeds removed from 1 half4 garlic cloves, peeled1 tablespoon plus ½ cup olive oil2 cups cilantro leaves with tender stems (from about ½ bunch)2 cups parsley leaves with tender stems (from about ½ bunch)2 cups trimmed arugula2 tablespoons white wine vinegar1 tablespoon chopped preserved lemon or 1 teaspoon finely grated lemon zestKosher salt, freshly ground pepper

Method