Place the salad greens in a large bowl. Add the red onion, pear, pecans, and blue cheese, and toss to mix evenly.
To make the dressing, place the maple syrup, vinegar, mayonnaise, brown sugar, salt, and pepper in a blender, and blend thoroughly. With the motor running, slowly pour in the walnut oil. Blend until mixture becomes creamy, about 1 minute. Pour over salad mixture, and toss to coat greens evenly. Serve immediately.
