Beat cream cheese and sour cream with electric mixer on low to medium speed until smooth. Stir in onion and garlic. Add 1/3 cup crumbled Gorgonzola or other blue cheese (1-1/2 ounces). Line a small mixing bowl or 6- to 10-ounce custard cup or mold with plastic wrap.
Spoon half of the cheese mixture evenly into a prepared bowl or mold. Sprinkle with 2 tablespoons finely chopped toasted walnuts. Top with remaining Gorgonzola mixture. Cover and refrigerate for 4 to 24 hours.
To serve, unmold cheese. Place on a platter and serve with crackers. Garnish with nuts, cilantro, chopped red peppers or basil. Makes 12 servings.