Place the arugula, lemon zest and juice, pine nuts, salt and pepper, to taste, and the garlic in the bowl of a food processor and pulse to grind. Let 'er rip and add the extra-virgin olive oil in a slow steady stream. Once all the oil is in, add the cheese and pulse to combine. Arrange the radicchio and romaine in a salad bowl, top with dressing and toss to combine.
Recipe courtesy of Rachael Ray, 2007