Preheat oven to 400 degrees. Butter a 1 quart casserole or gratin dish.
In a saucepan combine sunchokes, ¾ cup PLUS 2 tablespoons of the cream, ginger, garlic, salt and pepper over medium-low heat, stirring constantly to prevent burning. Let cook 5 minutes once hot to combine all flavors and soften the sunchokes.
Mix the remaining 2 tablespoons of cream with cornstarch; stir to fully combine.
Add to sunchoke mixture in saucepan and continue to cook 5-8 minutes (over medium-low heat) longer until the mixture begins to thicken.
In a small bowl combine the bread crumbs and pecans and stir to fully mix together.
Spoon the sunchoke mixture into the prepared baking pan. Cover the top evenly with bread/pecan mixture.
Place the baking dish of sunchokes in a larger roasting pan. Fill with hot water to reach halfway up the side of the baking dish to create a water bath.
Bake until done when top becomes golden brown; about 20-25 minutes. NOTE: if the topping begins to over brown, place foil on top and continue cooking.
*To make homemade bread crumbs: Toast bread and process into crumbs in a food processer or mini chopper. Extra bread crumbs may be sealed and frozen for future use. Recipe adatped from About.com