Place the turkey, breast side up, in a large glass dish. Rub the inside cavity of the turkey with 3 tsp of the salt. Sprinkle the remaining salt on the breasts and thighs of the turkey. Cover with plastic wrap and refrigerate for 3 days.
With the rack in the lowest position, preheat the oven to 350°F (180°C).
In a bowl, combine the mustard and maple syrup. In a large roasting pan, place the turkey, breast side up. Pat the skin of the turkey dry with paper towels. Brush with the mustard and maple syrup mixture.
Bake for 1 hour and 30 minutes. Increase the oven temperature to 400°F (200°C). Place the vegetables around the turkey. Continue cooking for about 1 hour or until a meat thermometer inserted into the thigh without touching the bone reads 180°F (82°C). Transfer the turkey to a serving platter and let rest, uncovered, for about 30 minutes.
In a bowl, dissolve the cornstarch in the broth.
In a large skillet over medium heat, soften the shallots in the butter. Add the maple syrup and continue cooking for about 4 minutes or until it starts to caramelize. Deglaze with the pastis. Add the broth mixture and bring to a boil, whisking constantly. Reduce by half. Add the parsley.
Serve the turkey with the vegetables and Tarragon Mashed Potatoes (see recipe). Drizzle with the sauce.
Try to avoid green bell peppers as they taste slightly more bitter.