In small frying pan, heat 1 tablespoon oil over medium heat; add onion and cook, stirring for 5 minutes
Add garlic and sage; cook 1 minute
Remove from heat; cool
In medium bowl, combine onion mixture, ground turkey, pancetta, breadcrumbs, and nutmeg; season lightly with salt and pepper; mix thoroughly
Season boneless legs with salt and pepper; lay on working surface skin side down to form rectangles
Working lengthwise, divide stuffing evenly down middles
Roll to form two 3x10 inch roasts; tie with butcher twine (stuffing will be visible down centre of each)
Preheat oven to 400; in large non-stick frying pan, heat remaining 2 tablespoons oil over medium high heat
Brown roulades until golden on all sides (about 12 minutes; mine took 6 minutes)
Transfer to roasting pan seam side down; add sage and halved onions decoratively
Roast until instant read thermometer inserted in middle reads 165F (45 to 55 minutes)
Rest 20 minutes; remove strings and slice thickly
