Put oven rack in middle position and preheat oven to 425°F.
Toss pears with oil and spread in single layer in a 17” x 12” shallow baking pan, then season with salt and pepper. Roast pears, stirring and turning over twice until pears are tender and beginning to brown, 20-30 minutes. Cool about 15 minutes.
While pears are roasting and cooling, place 1 pound Arcadian Harvest Salad Blend into a large bowl.
Whisk together shallot, vinegar, honey, salt and pepper, then add oil in a slow stream, whisking until emulsified.
Just before serving, add roasted pears, candied pecans, bleu cheese and dressing to greens and toss to combine well.
For the Candied Pecans:
Line baking sheet with foil; spray with nonstick spray. Combine sugar, 2 Tbsp water, and cream of tartar in heavy small saucepan. Stir over medium-low heat until sugar dissolves. Increase heat; boil without stirring until syrup is deep amber color, occasionally brushing down sides of pan with pastry brush dipped in water and swirling pan, about 7 minutes.
Remove from heat and immediately stir in pecans. Quickly pour mixture out onto prepared baking sheet. Working quickly and using 2 forks, separate pecans into individual halves. Cool completely. Break candied pecans apart, leaving each pecan half intact with some candied caramel attached.
Can be made 1 week ahead and stored airtight at room temperature.