In a small bowl whisk together the garlic, honey, porter, red pepper flakes, mustard, soy sauce and pepper. Add the chicken cubes, refrigerate for 1 hour and up to overnight.
Remove the chicken from marinade (reserve the marinade) thread the chicken through wooden skewers.
In a pot over medium high heat, add the olive oil and shallots. Sautee until shallots have softened, about 5 minutes. Add marinade and boil, stirring frequently, until reduced and thickened, about 8 minutes.