Preheat oven to 425 degrees F.
Season entire hen with salt, including the cavity. Push the wings back and rub the garam masala over the entire hen. Place on a lightly oiled baking rack set over a baking sheet and bake for 15 minutes. Brush with some of the glaze and reduce the heat to 375 degrees F and continue baking until just cooked through, about 10 to 15 minutes longer or until a thermometer inserted into the thickest part of the leg registers 160 degrees F. Remove from the oven, brush with the remaining glaze, and let rest 5 minutes before serving. Alternatively, you can sear the hens in an oven-safe saute pan over medium-high heat and then transfer pan to the oven to finish cooking.
Heat oil in a medium saucepan over medium heat. Add shallots and ginger and cook until soft. Add red chili flakes and cook for 30 seconds. Stir in chicken stock and peppercorns and cook until reduced by half. Whisk in maple syrup and tamarind paste and cook for 15 minutes or until slightly thickened, stirring occasionally. Remove from the heat and let cool to room temperature before using.