Cook the sugar and pecans in a small skillet over medium, 5 to 7 minutes or until the sugar has caramelized. Spread the pecans in a single layer on lightly greased wax paper on a large baking sheet. Let them cool completely and then chop into 1/2-inch pieces.
Whisk together the olive oil, vinegar, Dijon, garlic, salt, sugar, and pepper in a small bowl.
Layer the lettuce, pears, cheese, avocado, and green onions on a large serving platter. Drizzle with the desired amount of dressing, and top with the pecans.