For the pecans, combine the brown sugar, cayenne pepper and cumin in a bowl and mix well. Stir in the oil. Add the pecans and toss to coat. Spread the pecans in a single layer on a baking sheet. Toast at 350 degrees for 15 to 20 minutes or until light brown, stirring once. Let stand until cool. You may prepare up to 2 days in advance and store in an airtight container.
For the vinaigrette, process the apple and shallot in a blender or food processor until smooth. Add the vinegar and sugar. Process until blended. Add the corn oil and walnut oil gradually, processing constantly until creamy. Season with salt and pepper. Use immediately or store covered in the refrigerator. Shake well before using.
For the salad, soak the onion in cold water or wine vinegar in a bowl. Blanch the beans in boiling salted water in a saucepan until tender-crisp; drain. Rinse with cold water until cool; drain. Toss the pecans, drained onion, beans, mixed greens, grapes and pears in a salad bowl. Add half the vinaigrette and toss gently until coated. Sprinkle with salt and pepper; Crumble the cheese over the top and toss to mix. Sprinkle with the chives. Serve with the remaining vinaigrette.