In a skillet over medium heat, stir 1/4 cup of sugar together with the nuts. Continue stirring gently until sugar has melted and caramelized the nuts. Carefully transfer nuts onto waxed paper. Allow to cool, and break into pieces.
For the dressing, blend oil, vinegar, sugar, mustard, chopped garlic, salt, and pepper.
In a large serving bowl, toss lettuce, pears, feta cheese, avocado, and green onions. Pour dressing over salad, sprinkle with nuts, and serve.